>>58692321>The simple fact is that Chikorita does really poorly against most of the gyms in Johto, and its playstyle is more defensive rather than ‘press A to win’ like the other two.Second part is true, first part is false.
If you're using Chikorita effectively, it's arguably the most useful of the three in the context of a full team. But that's the thing, people only really judge starters by what they can do on their own, and Meganium (and by extension its prevos) are built to assist other team members, which isn't what people look for in a starter.
But as a support mon, Meganium slots a lot more nicely into any team for a playthrough. There's not much Feraligatr and Typhlosion can do that other Pokemon in Johto can't do better, whereas Meganium's access to dual screens isn't something that's easy to come by in the Johto games. Plus, it serves as a phenomenal support mon for the Geodude line, which is known for being extremely viable in Johto. It also sees some niche use in Smogon's Gen 2 OU (more than the other two) for whatever fanfic meta viability is worth.
It's also worth noting that Bayleef is practically a cheat code for Whitney specifically, especially if you're lucky enough to get a female one for that Attract immunity. But even then, resisting Rollout goes a long way.
It's true that it has gotten powercrept over the years, but Mega Meganium shows some promise. Triage is kind of unlikely, but really anything is better than Leaf Guard.