The help center provides some guidance about deleting answers
Answers that do not fundamentally answer the question may be removed. This includes answers that are:
- commentary on the question or other answers
- asking another, different question
- “thanks!” or “me too!” responses
- exact duplicates of other answers
- barely more than a link to an external site
- not even a partial answer to the actual question
One issue is that many low quality answers still have net positive scores preventing high-rep users from casting delete vote. This is particularly true of questions that make the Hot Network Question (HNQ) list. This results in users flagging low quality answers, but often these flags are cast on answers that do not fall clearly into the help center description of why some answers are deleted.
Once the answer is flagged, it goes through a community review process. Every once in a while the review process is inconclusive leading to an auto generated flag for moderator attention where a moderator needs to decide if the answer should be deleted. There have been complaints in the past about moderators reacting to these flags by deleting the answer (e.g., deleting). The only discussion I can find on deleting answers in general is this old question with a short answer and not a lot of visibility.
How do we want moderators to handle flags on answers that have net positive scores that seem to be poorly researched (i.e., worthy of down votes) and not obviously more than a partial answer to the actual question that have resulted in an inconclusive review?