This is not an argument to ban every form of rng from the game, as each case should be looked at individually : if you ask my opinion right now, I'd for example still keep paralysis, freeze or focus blast in the game for a number of reasons I won't devolve into in this post, despite them having some kind of rng factor. However if you can remove an rng element from the game with little to no cost, and without implementing a mod, be my guest!
Honestly, I find Paralysis to be a more broken Status Condition than Sleep, unless used by Darkrai.
Sleep "only" lasts two turns at most, and both the user and opponent know how to deal with it and what to expect from it.
Paralysis is different in the fact that unlike Sleep, you have a chance to do nothing every turn, no matter how small, on top of the fact that you lose 2 Stages in Speed.
Now, is Paralysis valuable for the Metagame to shut down sweepers? Definitely. But I don't buy the argument that Sleep is a broken Status Condition when it's limited to two turns and there's currently existing counterplay in Electric Terrain + the currently existing Sleep Clause, which no one had a problem with before Darkrai dropped.
Speaking of Electric Terrain and Darkrai, it didn't escape my notice that Darkrai was
nigh-blacklisted from being discussed here when people were giving out reasons for it to drop,
until OU decided to drop it. If OU hadn't done it, would we really have Suspected it at all?
Adding on to that, instead of simply caving in to what OU's doing, why don't we take a look at our own Tier to see what makes Sleep overbearing in OU vs Natdex.
1) OU doesn't have any viable Electric Surge users, we have Tapu Koko, who outside of Sludge Bomb, Darkrai does not want to go up against in general.
2) Tapu Fini, another setter of a Terrain that blanks Sleep, does not exist in OU, while in Natdex, it's another sleep-blanker that Darkrai really doesn't want to go up against.
These in combination with the moves in questions accuracy being abysmal makes it questionable to Ban the Status from a Meta that has actually legitimately answers to the playstyle that OU, who originally started the discussion, didn't have.
That said, let's continue to dissect this:
3-A) Only Iron Valiant and Darkrai are being looked to as abusers of Hypnosis from what I've gathered. The problem is being cited as Sleep, but it sounds more like Hypnosis is the only move being targeted by those looking to Ban the Status as it is.
3-B) As the only Sleep inducing move commonly being cited is Hypnosis, and given it's lower accuracy in comparison to the other moves that induce the same Status, it's easy to compare this to the likes of Fissure and Sheer Cold rather than Ban the entire Status altogether. Seeing as Spore and Sleep Powder have the same counterplay that Paralysis has, a Status we haven't ever talked about banning and is potentially worse than being Sleeped.
Now, to clarify the above point, do I think Paralysis should be Banned? Not particularly.
To clarify the point above it, do I think Darkrai should be Banned? Not particularly.
But if we're discussing Banning Sleep, a mechanic that's existed for years with only one Gen where it's gone due to GF themselves buffing it, then I think we should simply discuss whether we want to:
A) Ban the abused move
B) Ban the abusers
C) Compare our Tier to OU, and come to our own conclusion on whether what may be a problem for OU is really a problem for Natdex, particularly in a higher-powered Metagame.
If we do plan a Suspect Test to Ban Sleep altogether, then I'd like to look to Paralysis and ask what makes a 30% Chance to do nothing, the same chance as Fissure has to hit, combined with a 2 Stage drop to Speed, balanced with more widespread and consistent moves than Sleep, whose moves are often niche with awful accuracy or downsides to make up for the power of its Status.
On that point, without a Sleep Clause, I would even agree that consistency aside, the ability to do this potentially do this to the entire opposing team ad infinatum would be uncompetitive, but with a Clause we've had since forever preventing that, I don't think the niche Sleep moves we have are worth Banning the Mechanic when those moves aren't even consistent.
Z-Hypnosis is the only problematic form of Sleep in our own tier, imo. And notice, that problem would still be solved with the alternative method of Banning the move, rather than the Mechanic.
*Disclaimer: I don't actually enjoy Sleep as a Mechanic and wouldn't be mad to see it gone forever. Just don't like the arguments being listed to get rid of it.