I agree the Fediverse is not in a good spot for something like this.
I actually think this is where the identity system of atproto will be more impactful here as it allows a better verification system. I've been thinking lately you should be able to use hardware attestation + biometric attestation on apps to filter these emulated users out.
Most of this work is done via emulators if you have a hardware attestation process built in, it will stop most of it. Obviously you still have a problem with phone farms but those are much more expensive than emulators and there's a physical capacity to them.