That is why vBulletin has a "soft delete" functionality, which keeps a stub visible that says "deleted by <user>" while omitting all content. Soft-deleting a post would have exactly the same effect as editing the post to say "deleted," except that a soft-deleted post no longer counts towards the poster's post count and it looks better (it takes up less space on the screen).

Therefore, allowing a soft-delete functionality would still keep exactly the same accountability as allowing people to edit their posts to say "deleted," yet is still an improvement in terms of housekeeping. An additional benefit of soft-deletes is that mods can still see the original content of the post; this is not the case when the post is edited.

For all of these reasons, allowing something like a soft-delete would not cause any loss of accountability or other downsides compared to the current system, but would allow improvements in housekeeping and visual appeal.