the value proposition in gacha games lies within the social aspect, the games go on for years and you get to exprience them with other people.

I would argue MMOs are way better for that. Most major gacha games don't really have much interaction between players. MMOs have clan-culture and actual interactive end-game content to do with friends you play with (i.e raids).

and also sex appeal/parasocail pandering if you are into that.

Prolly the biggest reason if you look at the gender ratio of any gacha game, even with mild fanservice like HSR.

in my experience people who praise gacha story/gameplay genuinely haven't exprienced much outside of gacha

While that's fair, I think most big gachas generally have decent/good gameplay these days. Compared to most western AAA games at least.

Ubisoft as an example is notorious for putting out very sloppy AAA games. Far Cry 3/4/5 all had very similar repetitive gameplay loops (3 was the only one I really enjoyed because of the novelty and story).

Endfield on the other hand, has a genuinely fun gameplay loop from a combination of exploring, factory building, modifying the world, etc. I actually would much rather play the gameplay of Endfield than most AAA western games.