> In those days they did this by having physical public spaces for interaction, which we've since priced people out of through artificial scarcity of real estate via zoning laws.

IDK where to begin with this, because we clearly do have physical public spaces for interaction, whether free like parks or not free like coffee shops. People also hang out at each others' homes. Moreover, supply of public spaces increases when there's demand, much of which is being soaked up by social media.

You're also acting like we can't meaningfully distinguish between social media and other forms of communication and that we have to be all or nothing about it, which is a bewildering take. Even social media can be meaningfully distinguished in terms of design features. Facebook back when it was posting on friends' walls, no likes, comments, shares, friend/follower counts, or feeds, was fun and mostly harmless. LinkedIn was genuinely useful when the feed was nothing more than professional updates. They've all since morphed into toxic cesspools of social comparison, parasociality, polarization, disinformation, and other problems. Interoperability/federation doesn't solve those problems: most of the interoperable and federated solutions actually perpetuate them, because the problematic design features are part of the spec.