I genuinely think that USUM is one of the best Pokemon games ever made. I think it's up there with Emerald, Platinum, HGSS and BW2, and I don't understand people who treat USUM differently from these other 4 games.
Like yeah, I understand that SM/USUM have more cutscenes than other Pokemon games, but I don't think that is such a big deal.
I also find the Rotom Dex to be really cute. It doesn't annoy me at all.
Also, these are really small points compared to everything else that USUM does right:
>Battle Tree
>Battle Royal
>Battle Agency
>Champion Title Defense
>Mantine Surfing
>Ultra Warp Ride
>Alola Photo Club
>PokeFinder
>Team Rainbow Rocket plot
>Poke Pelago
>Pokemon Refresh
>Battle Buffet
>Kantonian Gym
>Roto Loto
>Etc.

This game really is up there with the best in the series.