It’s interesting to go back in time and look at what GUI programming was in the 90s. Windows got so many things wrong in this respect, especially when you consider that Smalltalk, NeXT or even System 5/6/7 existed before the Windows 3 API. Java did a really good job with Swing, but I feel the best was Mozilla with XUL – QtQuick is the only thing that comes close in effectiveness.
Well, consider Windows was made to fit on restrained systems. Smalltalk and proto-Cocoa were intended for larger systems and even then were sluggish on those, Macintosh Toolbox was weird (and everything that wasn’t Win16 wasn’t much better) with oddities like double pointers everywhere, and Swing was a decade later, let alone XUL or QtQuick.
Considering the competition at the time, Windows was actually pretty decent to programmers, all things considered.