Author here. Very confusing licence, is my main complaint (I speak also as the author of Svelte NodeGUI, which is built on top of Qt). The fact that there are hour-long seminars explaining the licencing (https://www.youtube.com/watch?v=m7etOQfrMiM) show that it's a real issue. I recall Qt for mobile has an even muddier story, with a different licencing/pricing model again.

Besides that, I also personally find it horrible to program with, because different elements have differents way of managing their child nodes (unlike HTML Elements, which have one consistent API). And of course I'm a JS dev, though NodeGUI does solve that. But maybe these aren't valid gripes.

Qt is awful. Its basically the equivalent of boost but for UI

first rule of qt is nobody talks about qt