>>33126838PSS, Trainer Customization, made Breeding way less of a hassle, gave you a way to see EV spreads on your pokemon, buffing Steel and Poison and nerfing Dragon with Fairy, Wonder Trade, Inverse Battles, Pokemon Amie being interaction similar to that of Walking Pokemon from HGSS, Dex variety, Overworld music, Restaurants being the best place to grind money and EXP, actually challenging without EXP Share so both inexperienced kids and veterans can enjoy, Freeze-Dry, Sticky Web, Parting Shot, Phantom Force, Boomburst, Nuzzle, and Power-Up Punch.
That's not even including more subjective stuff like overall pokemon and mega evolution design, but at the same time, you can't seriously hate every single pokemon design and mega evolution introduced in this generation. Lack of new pokemon isn't entirely valid, either, since Gen 4 basically did the same thing except with regular evolutions and baby forms instead of megas. Remove those and you lose 29 pokemon, left with only 77.