What's the endgame of a dead internet? Everyone leaves and most interactions happens in private group chats?
It's the serendipity of the original internet I'll miss the most.
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.
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.