Vision or not, Ben cannot survive.
Like Darth Vader, these two were only “redeemed” by one person. The whole galaxy would not forgive these Space Hitlers. It is a simpler ending to have them die, then to have them live. Ben would have to stay in hiding for the rest of his life from THE ENTIRE GALEXY and Rey would have to hook up with him in secret since she would be aiding and abetting A MASS MURDERER.
The more I think of the “Reylo” thing it makes me roll my eyes harder and harder.
Anyway, that’s my two cents on that topic.