You somehow think that they cannot act with impunity EVEN if they post, every single day, hour, minute or second?

Accounts with high-rep can downvote anyone with lower rep than them below (0) which automatically hides all their posts and comments and breaks any links to their posts and comments.

If a rogue account had an active post, at least there would be a chance that a higher-rep account could take action to reduce their rep, thus mitigating the amount of damage they could wreak by reducing the number of accounts they could de facto censor wholesale.

Yes, even if they were ranked below (0) they could still wipe out rewards on individual posts and or comments, but they couldn't wipe out ENTIRE ACCOUNTS.