I think you're underselling this, at the very least in the context of Venusaur vs Victreebel, because being able to sleep an opponent and use Swords Dance is allowing a mon to clear match-ups it wouldn't otherwise be able to, for example Sabrina, Rival, or Blaine. And while other mons are better in these match-ups (you can use a Water-type against Blaine and call it a day, or not use a Poison-type against Psychic-type mons), it's still something that Victreebel can do that Venusaur can't, and it allows you to not need a dedicated team slot for that weakness.
I don't think that a strategy with a 25% failure rate qualifies as efficient use of a Pokemon. I would rather try to make use of Venusaur's higher Speed (accounting for badge boost + stat EXP) to try to outpace Alakazam in the Sabrina/Rival fights than do...whatever Victreebel is supposed to do to beat Alakazam. Their HP/Special is the same so if Victreebel can tank a hit from Alakazam, so can Venusaur. Victreebel might be able to pull off Growth strategies, but that would require Potion support and isn't very efficient.
I neglected to include the relevant portion of the post in the quote, but I'm of the opinion that Bulbasaur should grind to 13 before Brock for Vine Whip. Aside from how much easier the fight becomes with it, it gives Bulbasaur more of a power advantage past Brock. It'll be 14 after Brock.
Gonna pop in here. We aren't speedrunning if this is what you are implying. The list has already banned the most commonly used Item Combo which is X Accuracy and an OHKO move. As for the fangame, I fail to see any relevance here with that. Additionally, we should not be comparing mons to one another and using that as a condition to tier. The Pokemon should be tested on its own merits. You can compare a mon to make a point or argument, but never when it comes to actually placing them.
The idea of "efficiency" presented in the various tier topics is fairly loose and not well defined, due to everyone having their own standard and idea of efficiency. Speed is a relevant part of it, but I am not suggesting that speedrunning the game should be the metric to use for efficiency. The metric I've decided for my personal use (total game battle turn count) is also fairly useless for tiering, as it's more focused on building an efficient team and route than determining how effective an individual Pokemon is, but I believe it gives a better idea of efficiency than testing a bunch of random Pokemon without consideration for their interactions or how to actually efficiently use them. For example, TM cost. The measure used for this tends to be "how many Pokemon can make use of this TM?", rather than the more accurate "which Pokemon make the best use of this TM?". Taking Parasect for example, if you're giving it TMs that other Pokemon can use better than it, like Body Slam or Swords Dance, there's no loss if Parasect is the best user of those TMs on the team. But if it's not, then in using Parasect more "efficiently", you are using the actually more efficient users of these TMs less efficiently, and the overall efficiency of the party is a net loss. Whether or not that is the case can be determined by identifying which Pokemon partner best with Parasect. A Pokemon's team compatibility is a vital part of determining its actual efficiency. What is the value of having something like say Psychic in a level-up pool? That value depends on how efficient it is to have the natural Psychic user in addition to another Psychic user that gained it via TM. This is a much more useful and concrete definition than leaving it as some undefined variable like "natural Psychic frees up the TM for another user". Okay, but is it actually efficient to have another user? That question goes unanswered.
I have no intention of suggesting that my idea of efficiency is more valid than anyone else's, but I am offering this viewpoint as something to consider. As a player that was new to the idea of "efficient" play, I found the tier lists and most of the information presented in the tier list threads to be fairly useless, and that's why I figured out my own guidelines. The tier lists are not good indicators of what areas of the game the Pokemon is efficient for or what Pokemon are efficient to pair with it, which is a vital part of building an efficient team.
Venusaur is by far the worst starter. It requires a TM to even be passable
So does Clefable, this isn't an argument. Without TMs, Charmander's best move is Ember until level 33 Slash on Charmeleon. And Charmeleon's Special is 65 compared to Ivysaur's 80, so on a neutral target it's actually the weakest starter without TMs.
No argument about Bulbasaur being the worst starter, just the comparisons with Bellsprout. Ivysaur's performance with Body Slam is clearly superior to Bellsprout's in the Cerulean-Celadon part of the game, particularly for Rival #4 and Surge. If you do Rocket Hideout first, Ivysaur's probably a Venusaur for Erika, way better than the Weepinbell that still has to hold off on evolving if it wants Razor Leaf. Without Body Slam, they're probably the same tier, but otherwise nah.