A lot of the QoL changes they made in gen 8 have really positively impacted my experience with the games: Adding nature mints Making it easier to farm money / exp candies Daycare improvements like being able to pass egg moves without breeding While likely accidental, the raid den exploits are super valuable because they make getting good/rare Pokemon a lot easier The pokeball tiers and rewards in competitive make online battling easily accessible and rewarding
It's so much easier to build a competitive team than it ever was before.
Making TMs not single-use was pretty great too, same with removing HMs. A bit of a step backwards in g8 with TRs, but at least they're really easy to get.
The most recent DLC also made EV vitamins cost less and added a way to reset EVs completely. There's also a way to use Pokemon from a previous game in competitive, which is really nice. And lastly, you can now give normal 'mons the ability to gmax instead.
In terms of dumb stuff, there are always a bunch of gimmicks that don't work very well \_()_/
This, pretty much. As a shiny breeder Gen 8 has so many QoL details.