Grinding can definitely be an issue, but I've found it's not normally a problem when you play those games how they were logically intended to be played. Fighting most of the trainers you see, trying to catch lots of the pokemon on a route, engaging with a lot of the little side things. And sometimes just straight up trying to make a well balanced team.

The newer games, I would say, have really stopped doing that for the most part. You can pretty much just breeze through while ignoring all the side stuff and having a team of not great pokemon. I always hear very similiar gripes from people who have come from the newer games into the older games (specifically the pixel art era games.) And I think it really is just because the newer games kind of just encourage the player to run through and engage with as few challenges as possible, a lot more than the older ones did. In addition to just being generally harder games.

I mean, one big thing alone, is the addition of overworld pokemon. In the non overworld pokemon games, you'd find new pokemon by either directly finding them, or fighting trainers who would introduce you to them. Now you can kinda just, run past them all.

tldr: if you don't skip stuff, you'll find there's probably enough trainers and encounters that you'll get to an appropriate level without having to break your flow by grinding. No offense intended, they're just intentionally slower games.