Lemmy and similar are not inherently more resistant to this. Actually, they are probably less resistant from a technical standpoint, since there is virtually no barrier to creating an account. I didn't even need an email address to sign up, let alone a phone number like the corporate sites require nowadays (not sure about Reddit, but Google, Facebook, and Twitter all require phone verification to register last I checked).
I fear that we are not ready for the wave of spam that will come as soon as the fediverse becomes mainstream.
On a more fundamental level, I don't know how to reconcile the competing goals of accountability and privacy.
Realistically, there is no way to distinguish AI comments from human comments. Not in any way that wouldn't become obsolete the day after it was implemented.
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