The subset of GUI software is much much smaller than the greater whole. I do agree though that any GUI programming on Linux is a pain compared to Linux / Mac.

The subset of GUI software is much much smaller than the greater whole. I do agree though that any GUI programming on Linux is a pain compared to Linux / Mac. However the proliferation of web based apps, even those running in electron shows how valuable a truely cross platform GUI framework that is easy to use would be. Google is trying with flutter and dart but last time I used it I felt it was still being iterated on far too quickly, maybe a bit ( maybe even now ) it will be more friendly to use.