Pretty much my biggest complaint with each game in the series. It always feels like we lose a few good ideas with each subsequent game, especially in recent Gens. Unlike a lot of games, IMO it feels like the greater issue is quality-of-life rather than actual mechanics (competitive randomness I feel is a more "how you play" issue).
If we could get a game with B2W2's difficulty settings (without the unlocking requirements) + USUM's overall difficulty, Gen 6/7's Super & Hyper Training, XY's O-Powers, Skippable Cutscenes, Trainer Customization, and Let's Go's Overworld Encounters we'd be in for a heck of a game. Heck I'm not even mentioning Secret Bases, Battle Frontier, Pokemon Amie, Pokemon Bank, Pokemon following behind you, or Let's Go's Sky mechanic. Is the Switch even capable of Soft-Resets?
Developing Pokemon, by it's nature, is a massive undertaking, especially given Game Freak isn't a huge company, but I'd be more than willing to have a half year+ delay and have a more polished product.