Idk if you can say that. Using Wayland may very well give better UX after all.

My prob with Wayland is more like, as shitty and 80s X may be, it's the one stable API that almost all F/OSS desktop apps and quite a couple highly specialized apps are developed against. The risk is loosing it all, especially as new desktop aren't coming in this millennium.

That's what XWayland is for, those clients probably will be able to keep working. As long as those clients exist then we'll be able to keep having things like XWayland and XQuartz, it's just translating X11 to the underlying window system after all.

Yes, probably. But still, what's the point of pulling support out from all apps if there are exactly zero new apps forthcoming? With getting hardware support/drivers for X already problematic, Wayland-native apps never able to run on non-Linuxen, and extant desktop app developers not even having capacity to qa apps on XWayland, the whole thing doesn't look like so good an idea on balance.

Maybe you are looking at it in a skewed way. I don't think there is a real use case for "Wayland-native" apps. There is no reason to do that unless you're building an embedded device or something, in which case you already probably picked Linux as the only kernel you're going to support. Most apps are just using a toolkit or some other kind of abstraction layer. If you don't have an abstraction layer then you probably have a lot of other portability problems to worry about if you want to get it working outside Linux.

Most apps just use a framework, and those frameworks more than likely already have a wayland backend, so you just automatically have a wayland-native app with proper hdpi, multi-monitor, etc support!