I often read the advice that if something does not work on Linux, then switch from Wayland to X11.
Also, 20% is quite a big userbase. What you are saying is like saying that Firefox is "gone" because "percentage".
Trust me, X11 is not gone.
(written from a browser that runs in a VNC session that uses the X11 protocol under the hood)
X is deprecated. Its maintainers do not want to maintain it. They want you to use Wayland instead.
The major DEs have removed their X code paths, or will in the next year. The toolkits will follow suit. X is a dead end for new and non-legacy software.
It's a dead end that allows me to have HiDPI (aka a 4k display) on Ubuntu 24.04 and use the VMWare GUI and OnlyOffice.
Wayland was launched 18 years ago and it still can't handle mainstream apps in common scenarios.
Downvote all you want, I'm telling you what I see. I had to fall back to X...
"I often read the advice that if something does not work on Chrome in the US Govt, try IE6." - This was still true as of last year.
"Trust me, IE6 is not gone" - me