Linux can answer the question, but you're considering Linux as a monolithic platform which it isn't. If you ask "how do you build a UI for Gnome / KDE / Android?" then the answers are pretty clear.
Linux can answer the question, but you're considering Linux as a monolithic platform which it isn't. If you ask "how do you build a UI for Gnome / KDE / Android?" then the answers are pretty clear.
Also, being KDE native means using QT which is a good cross platform toolkit anyways.
Tbh Qt is so big you've still got a few minutes of decision making after you've decided to use it. What parts will you use and how will you use them?
...but then feeling out of place on GNOME / GTK4 / LibAdwaita-land
Linux is a mess, but at least it's unapologetically so.
They've got unified themes that make GTK and Qt applications look nice alongside each other. Users who care will be using those. Users who really care might refuse to use your application because it isn't the toolkit they like, but you shouldn't lose sleep over satisfying such particular and demanding users. They're not paying you anyway.