I always interpreted that as a factor of the Plasma team being willing to offer compatibility for things that broke the freedesktop spec.
Whereas Gnome / Mutter for example appear to believe that if they don’t strictly follow spec it’ll perpetuate the fragmentation.
I tend to side with the latter perspective but use KDE + kwin on my desktop for gaming for Wayland + vrr (it’s amazing how smooth and responsive this is). Gnome really shines on the notebook form factor so I use it there.
Fedora runs at a twice annual release model and includes kernel and firmware updates within those releases whereas Ubuntu matches a kernel with a release.
Their packages, to me, feel much higher quality in terms of reliability and reaction time to reported bugs. They also test and guarantee updates for packages in their repos. I ran my college laptop through 15 system upgrades without any issues, nothing has been that reliable for me.
I enjoyed using Ubuntu for several years and hadn’t considered Fedora until they were the first to default to Wayland (f21) and never switched again.
You can do anything on any distro, so you end up just shopping for your fav package manager and default repo and staying there. I encourage you to play with all of them with a separated /home partition or so it’s easy to shop.
For X there was only one protocol, so they all wrote for x.
This also allowed some hacky things to be done that are questionable from a security standpoint afaik.
You don’t need a crazy server either. I got a cheap Intel Celeron motherboard for mine. Peaks at 10w and just hangs out streaming music and videos to our phones.