So much of the Kanto games, both what you can catch and most random trainers, being birds, bugs, and plants is a bit disappointing on replays. It makes a lot of sense, since that is what everyone would have access to and it lets Pokemon of other types be concentrated in Gyms, but I don't remember even Gold and Silver being quite that dull for that long.
I remember Sinnoh being both interesting yet very mundane, and there is a notion that Gen 4 was so boring and by the book that the series NEEDED some kind of shake up, so I pop in Pearl again (for maximum potential whiplash), and my opinion is ticking upwards. It is a lot fields and caves like Kanto, but Game Freak uses elevation, HMs, and field conditions to make them a bit more than straight paths- and going through it with a team that can organically shoulder all the HMs is a much better time. And I forgot how much I miss based Nob's translations, he makes Team Galactic so fun. The Pokemon selection is okay aside from the typical fire and electric droughts.
>>39780739As I recall, it is three things:
1) Game Freak assumed players would tackle Team Rocket and Pryce before Chuck and Jasmine when most players do not, causing the former to be noticeably low level.
2) Wild Pokemon are mostly in the 20s from Ice Path to Mt. Silver.
3) Despite these things, most of Kanto's Gym Leaders end up not being that difficult.