I haven't seen any cross-platform widget APIs that allow you to build a MacOS toolbar, for example―at least among the popular APIs. You mostly can only specify that the titlebar and the toolbar should be merged. Qt can draw something, but it will look like a Qt toolbar, not a Mac one.

So I don't see how WxWidgets is an outlier here.

It's fine for small apps and in-company utilities and isn't hard to use at all if you're a c++ house.