Oh wow xlibre was shit from the very beginning who could have predicted this? Super unexpected!

Reading the linked forum thread is a gift, so many crazy peope at the same place that accuse each other being DEI hires and lefties, but this is a gem:

You guys have no idea what a mess Xorg's source code is. I only made very small changes, but I had to spent HOURS on verifying each small thing, because changing only one line of code will cause some entirely unrelated part of the code to completely break in ways that you cannot even imagine.
You cannot even properly debug a lot of the time because you don't know which parts of the code use which functions. The code is a giant function pointer soup that is passed around everywhere and nobody knows which parts of the code use which functions as a consequence.
...

So exactly the reason why wayland happened.