For me it's still total immaturity everywhere in GUI and consumer hardware. The most performant mail client, kMail, cashes too much, when it has more than ten thousand of emails its performance is very bad it's preferences are somewhat crazy. Still a mess with DPI scaling. Still a mess with the mix of different KDE/Gnome/Qt styled applications everywhere. None of the modern distributions can turn off my monitor by DDC when entering dark mode after computer inactivity. I'l kee my hackintosh as long as i can, it handles hardware much more better than any other OS.