Qt and GTK apps don't usually spawn 5 processes, 300-400 MB of RAM, and take 100+ MB of disk space (because they always ship an entire copy of Electron) just to show a small window.
They solve the task at hand (cross-platform GUIs), plus some auxiliary tasks like cross-platform FS access etc etc. That's much cleaner and more principled than "screw it, let's ship a browser".