Like all frameworks, which are barebones libraries wrapped in opinionated organization, KDE/QT can be a lot when you need a simple UI.

I’ve used Nuklear to make simple, portable, UIs: https://github.com/Immediate-Mode-UI/Nuklear

Everything has trade offs; I might need to come up with my own way of handling some bit of state, but my projects aren’t big enough to need the software equivalent of a Costco.