If you're not logged on, then you wouldn't be able to post a reply.
You were talking about stalking and doxxing. Why would you need to post a reply?
Yes, you can set up a new logon but that can also be blocked,
But if the login was only created for the purpose of gleaning personal info for doxxing or stalking, what would the malicious actor care? How would the person being stalked belonged to the same person?
and doing so makes it more likely that the person doing it is banned.
Defeatable by creating a new account.
The people I know who were doxxed were not doxxed by their putting public details on X or other public forums.
If they weren't doxxed through Twitter, banning or blocking them on Twitter would not have helped.