Sure, Venusaur is the best Grass type Gen 1, but Venusaur sucks by comparison to the other starters! Your starter is typically your powerhouse, often your highest level pokemon with generally good stats, but Venusaur's offensive options are weak, so you rely on Stun Spore for utility? I'd prefer Thunder Wave (100% acc) and accept the miss against Ground types (which pretty much get destroyed by a single Surf from a decent Water type).
Razor Leaf is its "go to" move, even late game (55 base power, 95% acc) - there's no equivalent of Flamethrower or Surf (95 base power, 100% acc) - Solar Beam is more like Fire/Hydro Blast (120 base power - 100% acc in exchange for being a two turn move though). The upside is that Rock/Ground types often stack Defense over Special, but that's not true of Water types.
I don't ever worry about gyms (outside of mods or unusual runs), and I see the pokemon is so unspectacular that I can't imagine ever wanting it. The other starters just have that extra punch in their move sets.
Charmander has a rough start, but it's not *that* bad (Geodude and Onyx resist Fire, sure, but their Specials are low so Ember will get something done, there aren't any rock moves at that stage). Misty sucks, but you can pick up a Grass type nearby (and hey, Oddish and Bellsprout both learn Cut - gonna need someone to learn that
) or you can get Pikachu in the Viridian Forest (not recommended). Surge - well Diglett cave is right next door, Dig was picked up earlier, or just have a Nidoking for early game easy mode (or Kadabra).
Squirtle doesn't struggle against Erika - it can learn Ice Beam and will almost surely outspeed just about everything in that gym (and Ice Beam will utterly destroy Lance later on).
I guess my experience is that a Grass starter doesn't help me do anything I couldn't already do - the Fire and Water starters give me options. Whilst the other Grass types aren't as a good, they're available early, whereas Water types often require Fishing or Surf (both options come after Pokemon Tower) and Fire is just rare.
KnightExemplar wrote:Of the three starters, Venusaur is actually the best one to solo-play.
Perhaps, although speed run tactics used to run Blastoise (I think the current strategy is to use Nidoking).
I think I'd still take Squirtle for a *regular* single pokemon run - Dig for Surge, Ice Beam for Erika (and Lance, and Blue's Venusaur). That leaves Blue's Alakazam, but it has no type advantage. Venusaur is going to suffer against Lorelei - you have no type advantage against Jynx (and you don't learn any moves to cover Ice), and can you really one-shot that Lapras with Razor Leaf?