>>56206699NTA but yeah it's funny. D/P need the moment-to-moment speed boost but improved grinding's big picture more vastly than anything before, but 1-3 feel faster in general while having the fewest tools to increase gains.
Sinnoh does have an abysmal variety though, and while some will say the same for Johto, I personally always end up with a different mix by the time I enter Union Cave; the route north of it just smashes you with new shit like Mareep(RIP Crystal), Hoppip, and Wooper. Plus since that first part of the game gets done in under 2 hours, the times I start a playthrough at night are inherently different from the ones I start in the morning. I haven't replayed the start of Gen 4 nearly as much but I remember having difficulty finding even one team's worth of mons I wanted to use