They never learn do they ?

You can always repost quality content that you would like to share with the Lemmy community.

Sadly all the mods I asked before deleting my account did not respond or said they where not interested on migrating

Both? I did for beehaw and a smaller one waited a day for both, neither responded.

Would it be ethical to start saving useful reddit post on lemmy ?

Well when other instances outright ghost your application people.will either discard the fediverse or join the ones with auto accept be it LM or mimmthe one I joined.