Exactly. Preservation of obscure knowledge is important, but it does not take priority over peoples' privacy, security, and personal choice.

I think frequently making new primary accounts is a good compromise between preserving obscure knowledge and preserving privacy. A few times a year I'll even check my old inboxes just in case I can help someone since I myself have gotten lucky messaging inactive accounts about really obscure topics and getting a response.

You would still have to take additional measures if you post in some communities with any regularity.

I don’t see how someone posting a helpful answer to a question destroys their identity, I guess it could be mixed in with unsafe or embarrassing things but please can people take the time to go over each message to see if it really needs deleting? It might be a lot of work but it will do so much good compared to indiscriminately wiping everything and breaking the history of conversations other people were involved in without their permission

Again, no.

You do not need permission to withdraw your side of a conversation you engaged in.

It is kinda sad. Morally I think you are wrong but from a pragmatic perspective I have to agree.

We are getting to a point where the 'approved' really narrow consensus moves so fast you never know what will be used to harass you in the future.