Gonna put out my 2 grains of salt on the situation of what's going on. Specifically, Custap Berry
.
To me, Custap Berry is an uncompetitive item. It's pretty much the bridge between gimmick and uncompetitive, and I believe it leans towards the latter. Let's take an example of Custap Berry in action:

Primarina @ Custap Berry
Ability: Liquid Voice
Tera Type: Water
EVs: 252 HP / 252 SpA / 4 SpD
Modest Nature
- Hydro Cannon
- Moonblast
- Aqua Jet
- Endure
^ We have a Primarina here with a pretty standard moveset of Moonblast + Hydro Cannon + Aqua Jet + Endure. Now suppose we put it up against my Archaludon

Archaludon @ Choice Specs
Ability: Stamina
Tera Type: Steel
EVs: 252 SpA / 4 SpD / 252 Spe
Modest Nature
IVs: 0 Atk
- Flash Cannon
- Draco Meteor
- Thunderbolt
- Aura Sphere
^ My Archaludon is a Choice Specs moveset of Aura Sphere + Thunderbolt + Flash Cannon + Draco Meteor. Now, normally if I was say... Power Herb and Electro Shot, I win this matchup any day of the week. However, when you include Custap Berry in the mix...
252+ SpA Choice Specs Archaludon Thunderbolt vs. 252 HP / 4 SpD Primarina: 276-326 (75.8 - 89.5%) -- guaranteed 2HKO
252+ SpA Primarina Moonblast vs. 0 HP / 4 SpD Archaludon: 237-279 (73.8 - 86.9%) -- guaranteed OHKO
^^ Me simply not having Protect or Power Herb + Electro Shot means that I cannot win this matchup. Now, one could argue this is simply a teambuilding error -- and you're right. But... Unless you specifically have Power Herb and Electro Shot, or Protect as an alternative option, Archaludon doesn't beat Custap Berry Primarina unless there's a mistake in battle, or an EV mishap. And even if you do, it could have Protect to stop this (this isn't likely at all but it is an option). Now, if you take into account what Custap Berry sets usually have, it is Endure and Custap Berry -- with the potential for maximizing an offensive stat, or maybe EVing to live a specific hit. This is perfectly manageable, you may ask yourself, they're always almost locked into an entire item and move slot. This is easy to beat. Well then... let's look at some conventional ways you can beat Custap Berry, and how much of a risk they are.
1) Protect. This is a very concrete solution to beating Custap Berry. Usually they're slower than you and they click Endure the turn you knock them down into Custap range. But would you use it for something else, or is it natively a Custap Berry answer?
2) Priority. Priority is also pretty easy as a method to beat Custap Berry. It is technically higher than 0 priority whilst being lower than +1 priority -- so that's pretty good. There's many pokemon with priority that have/use priority moves for Custap esque situations. If you can fit it on your team, you should. IF you can fit it on your team...
3) Knock Off. Remove the Custap Berry altogether. Awesome. Now what would happen if they used an actual damaging move? You need to think about the advantage you gain from doing this -- as either it's an amazing payoff, or a wasted move as you are in OHKO range the following turn.
4) Unnerve. Same concept as Knock Off -- negate the threat of Custap Berry as a whole. Your options for this though are kinda... well, not wanting to use Unnerve.
There are other options as well like stalling or hard reads, however, I don't think a single item that lacks a genuine answer to it is not worthy of being in this tier -- or any tier with such a controversial item. The thing about Endure is that it's the same priority as Protect, but you, if it reaches that point, are at 1 HP for the whole turn. No damaging move can go past Endure, and that's the most common form of winning games in 1v1. Any good 1v1 player can prepare and/or beat Custap Berry. Many pokemon could beat all variants of a specific pokemon(s) -- such as Iron Valiant beating all Regidrago save for an in-battle crit or error. This item is essentially a more restrictive Quick Claw, and Quick Claw is banned for its uncompetitive nature of gimping wins. Custap Berry does nearly the same thing, and unless you have a status that inflicts damage against the Custap Berry pokemon, you're going to need to try to survive the following turn. At least with Booster Energy, you KNOW what's going to happen -- as it either has a Life Orb boost to every stat barring Speed, or an unrestricted Choice Scarf boost for the Speed stat. The difference here is you know what Custap Berry does, yet you cannot play around it without some heavy investment. Between the variables within Custap Berry, the linear ways to actually beat it, and the fact that well... YOU DON'T NEED TO BRING IT and can beat the mon that attempted to beat the Custap variant of it, I feel like Custap Berry needs a ban. If it isn't banned, I'm totally fine with that. I get where the other side of the argument is with the skill cap of using it. But in my opinion, that same skill cap makes this item (currently) possibly the most uncompetitive item in 1v1 as of now -- and I prefer to have skill in my games -- not undeserved wins due to you "being faster".

To me, Custap Berry is an uncompetitive item. It's pretty much the bridge between gimmick and uncompetitive, and I believe it leans towards the latter. Let's take an example of Custap Berry in action:

Primarina @ Custap Berry
Ability: Liquid Voice
Tera Type: Water
EVs: 252 HP / 252 SpA / 4 SpD
Modest Nature
- Hydro Cannon
- Moonblast
- Aqua Jet
- Endure
^ We have a Primarina here with a pretty standard moveset of Moonblast + Hydro Cannon + Aqua Jet + Endure. Now suppose we put it up against my Archaludon

Archaludon @ Choice Specs
Ability: Stamina
Tera Type: Steel
EVs: 252 SpA / 4 SpD / 252 Spe
Modest Nature
IVs: 0 Atk
- Flash Cannon
- Draco Meteor
- Thunderbolt
- Aura Sphere
^ My Archaludon is a Choice Specs moveset of Aura Sphere + Thunderbolt + Flash Cannon + Draco Meteor. Now, normally if I was say... Power Herb and Electro Shot, I win this matchup any day of the week. However, when you include Custap Berry in the mix...
252+ SpA Choice Specs Archaludon Thunderbolt vs. 252 HP / 4 SpD Primarina: 276-326 (75.8 - 89.5%) -- guaranteed 2HKO
252+ SpA Primarina Moonblast vs. 0 HP / 4 SpD Archaludon: 237-279 (73.8 - 86.9%) -- guaranteed OHKO
^^ Me simply not having Protect or Power Herb + Electro Shot means that I cannot win this matchup. Now, one could argue this is simply a teambuilding error -- and you're right. But... Unless you specifically have Power Herb and Electro Shot, or Protect as an alternative option, Archaludon doesn't beat Custap Berry Primarina unless there's a mistake in battle, or an EV mishap. And even if you do, it could have Protect to stop this (this isn't likely at all but it is an option). Now, if you take into account what Custap Berry sets usually have, it is Endure and Custap Berry -- with the potential for maximizing an offensive stat, or maybe EVing to live a specific hit. This is perfectly manageable, you may ask yourself, they're always almost locked into an entire item and move slot. This is easy to beat. Well then... let's look at some conventional ways you can beat Custap Berry, and how much of a risk they are.




There are other options as well like stalling or hard reads, however, I don't think a single item that lacks a genuine answer to it is not worthy of being in this tier -- or any tier with such a controversial item. The thing about Endure is that it's the same priority as Protect, but you, if it reaches that point, are at 1 HP for the whole turn. No damaging move can go past Endure, and that's the most common form of winning games in 1v1. Any good 1v1 player can prepare and/or beat Custap Berry. Many pokemon could beat all variants of a specific pokemon(s) -- such as Iron Valiant beating all Regidrago save for an in-battle crit or error. This item is essentially a more restrictive Quick Claw, and Quick Claw is banned for its uncompetitive nature of gimping wins. Custap Berry does nearly the same thing, and unless you have a status that inflicts damage against the Custap Berry pokemon, you're going to need to try to survive the following turn. At least with Booster Energy, you KNOW what's going to happen -- as it either has a Life Orb boost to every stat barring Speed, or an unrestricted Choice Scarf boost for the Speed stat. The difference here is you know what Custap Berry does, yet you cannot play around it without some heavy investment. Between the variables within Custap Berry, the linear ways to actually beat it, and the fact that well... YOU DON'T NEED TO BRING IT and can beat the mon that attempted to beat the Custap variant of it, I feel like Custap Berry needs a ban. If it isn't banned, I'm totally fine with that. I get where the other side of the argument is with the skill cap of using it. But in my opinion, that same skill cap makes this item (currently) possibly the most uncompetitive item in 1v1 as of now -- and I prefer to have skill in my games -- not undeserved wins due to you "being faster".