Ok I know I said that I'm fine with RB Bulbasaur being Top, and I still am fine with it, but I thought I'll just clarify why I lean more towards High (I wasn't going to but people seem to keep discussing it so...).
Grass is resisted by so much stuff. Vine Whip and Razor Leaf are awesome if they aren't but there are many times where they are. Before you reach Body Slam, all of these are used by various trainers:
- Charmander
- Weedle
- Kakuna
- Caterpie
- Metapod
- Nidoran-M
- Nidoran-F
- Pidgey
- Ekans
- Spearow
- Zubat
- Grimer
- Koffing
- Pidgeotto
- Charmeleon
- Oddish
- Bellsprout
- Butterfree
Some of these appear only once early game, but many of these appear quite frequently (Route 3 is particularly brutal since everything there resists Grass except Jigglypuff and a few Rattata). Now, OBVIOUSLY Bulbasaur can beat most of these easily anyway because they aren't very strong. But to do so in the fastest way possible it has to turn to Tackle. I have no idea how other people play Bulbasaur, or how much they choose to level it at the start, but in my experience Tackle is a 3HKO at best on most of these things. For me, that isn't what I'd call efficient (in relative terms anyway), although others may define "efficient" differently (hence why some people are arguing Top and others High). I'm not sure whether this is a legitimate argument, but Pidgey/Pidgeotto are particularly annoying because Sand Attack often makes me miss, adding more turns.
So yeah, then you reach Body Slam and teach it to Bulbasaur/Ivysaur (assuming it's available; if it isn't then Venusaur is significantly worse). It improves quite a bit as a result. But Body Slam doesn't change the fact that Venusaur struggles at more points in the game than I'm comfortable with. The absolute worst is Pokemon Tower, but Cycling Road is also horrible thanks to all of those bulky Poison types (at least it also has Machop/Machoke and Voltorb as Razor Leaf prey though). There's also those routes between Fuschia and Lavender that have all of those Bird Keepers and Bikers and Lasses/Beauties with Grass types, but it isn't as bad since the other non-grass resistant pokemon cancel it out a bit (not completely, but a bit).
I'm not denying that Venusaur can beat pretty much everything. So can lots of things. But in my experience, for higher level opponents that resist Grass, it can take multiple turns. It is particularly noticable early game, before Body Slam. Basically, I have trouble seeing how a pokemon that has to rely on weak Tackles early game to get around the many things that resist Vine Whip before becoming a pokemon that has underwhelming performance at certain points even with Body Slam can ever be Top tier.
Maybe it's my own fault for thinking this way though. Have I been using Bulbasaur incorrectly all this time? Other people seem to have had different experiences with Bulbasaur than me (or perhaps they have had the same experiences but are interpreting them differently), and if the popular opinion is "Bulbasaur is Top tier in RB", then it should be placed there. Just don't expect me to understand it.