Edit buttons don’t necessarily improve anything. In fact they can boggle communication.
Some might change their comment, belatedly seeing their lack of clarity, leaving replies hanging like meaningless tripe. The less ingenuous might even be inclined to update the meaning of their comment to cover the track of their hurried stupidity and/or undermine critical responses.
We don’t need to edit. We just need to better consider what we write. Don’t rush. Comment less. That’s my advise I don’t stick to.