Sorry but what is to stop actual humans from signing bot generated or false content using their private keys? It also creates incentives to steal other keys. What will happen if your private keys get stolen and they start being abused by someone else?

This sounds overtly Orwellian mixed with a PKI disaster.

This is not a technical issue that can just be solved with crypto. See https://www.cs.auckland.ac.nz/~pgut001/tutorial/T2b_Signatur...