Everything about QT is complicated. Everything in QT is non-trivia especially due to it's use of C++. Signals themselves are a bit tricky, and frankly a kind

Everything about QT is complicated. Everything in QT is non-trivia especially due to it's use of C++. Signals themselves are a bit tricky, and frankly a kind bloat, in that they are yet another abstraction that is not actually needed. Signals, which are related to the event loop and threading, create a bunch of potential issues that can't really raise their ugly heads in JS/Python, and even in a multi-threaded language like Java are a bit easier to deal with. QML is quite good for a narrow range of things, but if you start to go outside the bounds of what it was intended for it goes of the rails. You still need to know C++ for builds, and, C++ integration doesn't work particularly well. IDEs do not refactor well in C++, don't pick up as many errors, cmake is weird. QT has some amazing things (collections) that without, frankly, I don't think I would even use C++, but they all come with hints of weirdness. QT written today, for a narrow platform, in a single language, hopefully more modern - would be something different.