5 years down the line - assuming they've addressed things like primary monitors by then - I'm sure I'll happily switch. Right now they haven't, So I'm going to stick with something that I know works.
You seem to be implying everyone interested in Xlibre has some weird religious fervour: Maybe some do, but personally I just don't like have my stuff broken, then being given a plate of shit, and then being told I have to like it because it's "new".
Yes, X11 is "old". You know what else is "old"? Making processors out of silicon! Let's make them out of yogurt! Sure, the new ones may lack functionality, but you don't want to be on the wrong side of the culture war, do you?