Why build something from scratch when Wine/Proton is already there and is pretty much the same thing?

Of course that would be the trivial (if still very complicated and expensive on its own) part, incentivizing developers to invest the amount of resources needed to port their games to a new platform (which would have single digit % market share at best) would be a lot harder.

Sure there might be some risks. But I don’t really see why MS would be bothered to actually try and kill Wine. The risk of antitrust etc. would be very high and MS wouldn’t gain too much from this anyway.

Besides.. the Supreme Court already ruled in favor of Google over the Java/Oracle thing not sure how would this be much different.