"High quality" depends on how you measure quality. If you're judging by looks and how many buttons it has, then yes, I think it takes the cake. But I honestly appreciate the current Linux design paradigm. GTK and QT are both awesome GUI toolkits, and compliment each other nicely. GTK does a wonderful job of filling the MacOS gap, by making it easy to create simple but effective UIs. QT, on the other hand, offers a more stable and "complete" experience, pretty much catered towards people familiar with the Windows/.NET development workflow.

Like the other commenter said, I just don't see anywhere Linux is particularly lacking. It has first class support with DAWs like Reaper and Bitwig, it has pretty great video editing chops with apps like Davinci Resolve and Kdenlive, and it almost has a complete photography setup, at least once GIMP switches to GTK+ and Darkroom gets a few more features. All of those are "high quality" apps, and they're also free: a pretty massive distinction from the MacOS software you might pit against it.