Haven't actually played any of the gen 7 games yet (although I do own both Sun and OmegaRuby), but this is still something I've noticed. To be honest I just don't have much faith in GameFreak to make a good game anymore. They created a great game in the 1st gen, expanded on it in pretty much the perfect way in the 2nd gen. Refined it in the 3rd and 4th gens, and since then it seems like it's been more about simplification than either revolution or refinement. I guess that's not a bad thing. I don't really want a revolutionary Pokemon game, I want them to stick to what made the games great in the first place. But I also want them to add things on top to make each gen actually better than the previous one, not just prettier. I think gens 2-4 did that really well. They could quite easily have added an easy mode too which could have been the simplified version to attract more people, while retaining the current difficulty for a normal mode or even have added a hard mode too.
Oh and I've always wanted them to make the leagues better. They kind of... totally suck at the moment. You just walk up, battle the elite 4 + champion and are declared the new champion. I'd love it if they took a page from the anime there and actually had a proper tournament using your rival/s a bunch of randomly generated trainers, maybe some trainers that you'd faced in a one off battle before and maybe even the odd gym leader (randomly drawn too, to give it some replayability). And then only when you win that tournament can you move on to face the elite 4.