I liked the improved graphics, they feel more like in the anime, manga, and artwork itself. Small details like trainers using different Poke Balls and interacting with overworld Pokemon was nice. SM had little to no minigames, but Ultra SM gave us Photo Club, Mantine Surf and Ultra Space. The Pokemon Snap clone was also fun. Battle Royale could have been nice but they messed it up really badly. Also, being able to obtain Apricorn Balls and the massive amount of music is great. Level scale is also pretty great compared to XY, and some trainers felt stronger overall. It was nice to see them try something different than Gyms for once, and getting rid of HMs was pretty great. Finally, Pelago was definitively the best feature in the games, being able to breed, raise happiness, train, obtain certain items and berries in masses at the same time makes competitive perfect for people without a lot of time.
They fucked up with cutscenes and forced tutorials. Story tries too hard to be BW but it falls in stereotype characters and scenarios. The whole Kanto pandering is pretty cancerous. The lack of triples and rotation battles was awful, especially because even double battles lag more than in XY. Many new Pokemon (especially Tapus) fucking ruined competitive. Pikachu getting a lot of things again (6 new forms, 2 exclusive Z-Moves, a new evolution), and Charizard being the Fly Poke Ride really screamed KANTOOO all over the place, as well as Alolan Forms being exclusive for Kanto Pokemon. Characters being extremely forgettable and the game being more about Lillie's mommy issues as well as the extremely linear region makes it feel more like a series than an actual videogame. SOS battles can be a real pain. The main character is expressionless for 90% of the cutscenes, and the shiny lock is still present for every new legendary. The lack of another region made this generation feel kinda empty as gens 3, 4 and 6 have another region to complete the dex and obtain different features.