How do you have an unstable desktop? What card and or programs are you using?
In 20 years of desktops I’ve had issues with Nvidia cards, yes, and currently my KDE has a weird rendering issue where a specific window of my editor can flicker like once or twice a day, which is fixed by clicking it.
KDE4 was a hot mess back in the day after initial release, but it seems they learned their lesson and 6 seems quite fine (upgrading to that soon myself) I’ve mostly done fedora and Ubuntu desktops and honestly they’re a breeze.
So what exactly is it that you’re using that you have so many problems?