The only hoop you have to jump through is using a Nitter instance. And the most dangerous abusers are most likely going to be determined enough to where doing this or creating a new account is not a deterrent.

False security is worse than no security. If people trust that the block function is reliable at stopping people from seeing your posts, and then those people post things publicly that they wouldn't share otherwise, that is leaving more people vulnerable than having no way to stop people from seeing your posts.