that would be good
because:
[title]imagine if:[/title]
you were [u]writing a new post[/u] (like me rn)
but you accidentally posted with a gramatical error
then you could [b]edit[/b] and remake it whitout gramatical errors
also, it could appear like in youtube when [u]a comment gets edited[/u] and it could appear in the right of the post [b]"edited"[/b]

Good idea

I thought of that long ago