Just my 2c in addition to the list above. On it.wiki we are struggling with LTAs who use the trick "register on other wiki projects then autocreate an account on it.wiki". A filter blocking autocreateaccount based on specific patterns was of big help in reducing the successful attempts very close to zero. Between January 2023 (filter creation) up today the filter reacted 13763 times just against this individual LTA. Similar filters covering new patterns linked to that LTA abuser reacted over 3200 times. Note that those filters did not discourage this LTA, but at least saved a lot of work to patroller since the automatic block was enough to provide kind of dam. By the way, this filter was exported upon request to other wikis struggling with the same LTA. One of the typical pattern used, BTW, is using personal street addresses or other sensitive information as part of the username, so they also need suppression.