I bet almost everyone wants something they don't have, and see everyone else as having it all. This is not true most times. Many people have miserable lives for many reasons and not just our flavour. Some are worse than autism, some are not so bad, though how you measure such things is another matter.
Harken to the words of Vladimir Bartol: "Nothing is an absolute reality; all is permitted"
In other words we make our own realities, with nothing to play with but the hand we were dealt.
Maybe he is, but you're not speaking objectively. If you were dead I'd be a little more inclined to agree with the 0% chance!
He may be more likely to keep finding new relationships, but how can you possibly know that only joy, not suffering, comes to him that way? You don't, you just think that's the case.
Did you know that heat can flow from something cold into something hot? It's highly unlikely to happen, but it's not impossible, reality isn't what we think it is in all sort of ways.