what’s your point? if flatpak makes it easier for developers to package their software and easier for users to install it, there’s nothing wrong with it being famous
the package is maintained (will continue to install on modern ubuntu versions), but the software is unmaintained (no bug fixes, no new features, will stagnate and eventually become obselete as incompatible with future desktop standard modifications)
it’s that wayland wasn’t ready, and now is ready. it took a long time, because building a new protocol like that takes a while if you want to do it well, and lots of coordination between many people. it still has issues, but they’re being adressed. slowly, because x11 was full of half-assed solutions done quickly, and they don’t want that to happen again
X11 being reliable because Xorg devs aren’t stupid
xorg devs are wayland devs. nowadays, most of the people that used to work on xorg now work on wayland. they’re not stupid, they realised that x11 is too dated for modern systems (see asahi linux) and now are working on a replacement
to answer to question in the title, on top of what was already said: i just code them myself. of course, it doesn’t work for everything, but for simple programs, i can write a script or a proper thing that does the specific task i need!
i know i’ve wanted something like this for a while. i really didn’t want to have to figure out how to get the existing keyman keyboard layout to work on linux, because fcitx works fine for all my other input needs, and i already knew how fcitx worked as i made an addon to get on-screen keyboards to work with it a while back…
as i know not many people would dare venture in the world of fcitx addons, due to the quite horrendous state the documentation is in… so if i wasn’t gonna do it, likely no-one else was, so i did it! and shared it with everyone, because the worse that could happen is that someone helps me make it better!