25 years ago, I chanced upon a book called Republic 2.0, by Cass Sunstein, and I wrote a fairly detailed critique of the concept that people would actually isolate themselves online and exacerbate tensions and conflict by participating in enclaves and not interacting with those who disagreed:

https://www.markwelchblog.com/2002/01/21/54

I was right, and I was wrong. What I missed: oligarchs and media operators would deliberately create propaganda silos to exploit people. Sunstein’s focus was on people making their own autonomous choices, but I didn’t recognize that aggressive evil people would deliberately seek the worse possible outcomes.

I also did not expect potentially “neutral” portals (Google, Facebook, Amazon, etc.) would themselves amplify and worsen the tendencies, for their own profit.