This is great thanks and I agree with you 100%. I only left out traditional social media because the problems are glaringly obvious as you point out.
I think you are conflating aggregation with algorithmic fuckery. Proprietary rankings and bot manipulation are kept under careful lock and key because everyone has their own secret sauce to defraud investors.
This is why you "used to" enjoy reddit along with everyone else. The upvote system wasn't a bad idea before it became completely corrupted by propagandists. It did have some organic problems with hive mind but nowhere near what it has turned into.
I've been wondering lately if it is the sats themselves or the intellectual barrier of lightning / minimalist design that minimizes the spam. We should explore both in depth. But like with many things you don't have to be perfect just on the right track. The same way traditional socials spiraled out of control, this site might spiral into control!