a glance, I don’t see a problem. Isn’t social media already a system for rating social credit?

Yes and no. There's a difference between having a centralized/agglomerated/global score (e.g. karma on Reddit) and having individual posts/comments ranked. The consequences of said centralized ranking being decided in an opaque manner by a reactionary dev.

think the problem with social credit scores is when they’re mandatory and can limit things like housing access.

Yes I agree FICO score is fucked up

Filtering posts on opt-in social networks just sounds like a reasonable tool for moderating decentralized platforms.

So is having a community driven mod team, which is having that power not centralized by a (group) of devs across multiple decentralized instances.

To quote @RiverRock@lemmy.ml:

I mean most cults have voluntary membership too, it doesn’t make the techniques of social control they employ any less harmful