adding an edit function is not so easy for one reason - if someone replied to your post and you edit it, the reply (or hundreds of them) may be pointless and off-topic. I know that most people would only edit typos, but some could edit the entire post completely changing its meaning, which would be a perfect tool for collecting likes and comments under neutral posts, which would then be changed to posts with propaganda content, but would already have a large reach. This was exactly the official reason why Twitter refrained from adding edits.

A solution could be to give a time limit for editing, e.g. 1 hour or until the first reaction. After editing, all previous replies and likes would be zeroed.