It just gets a bit smaller. See Mastodon, and why most people's criticisms of it are in fact its strengths. For ~5% of the current internet.

One of two possibilities I foresee, unsure which will play out:

1) People surrender their perceived anonymity in favor of real interactions, embracing some kind of digital ID that ensures some platforms are human-only.

or

2) AI gets good enough that people stop caring whether they're real or not.

I bet my money on 1). Verifiable credentials are currently in the making, I can build products around this in my head immediately (a good sign that someone smarter than me has it figured out already), and huge platforms know so much about you, they’re almost there. It’s going to make interactions online safe, solve fraud, make everything personalised and wholesome. At least that’s going to be the narrative. Just wait for it.

The problem is it will be the narrative and not the reality, which just promotes the system as untrustworthy and pushes people away from it.

I think #2.

As they join the web of reputation, and they start protecting their own reputation.

I mean we are already knowingly, increasingly, interacting with chatgpt instead of real humans.