"Win32 however can’t resize the most basic window without flickering - which is why every decent Windows app uses its own non-native GUI layer."
This is so extremely wrong it's not even funny any more. WS_CLIPCHILDREN and WS_CLIPSIBLINGS are the key here. Of course, many people don't understand them (eventhough it's not hard and the Petzold came out, what, 25 years ago?) but win32 is very well understood by now and it's trivial to make extremely fast (by today's standards) UI's with it, and relatively easily, too.
Not OP, but sure, if I spend a few hours as a new Windows programmer I can finally make my native Windows application not flicker on resize, but that's most likely not it, there's probably a stload of other things I have to spend a few hours on to get things somewhat properly-working. It's a massive cost compared to what default web already offers.
Then I have to repeat that same years-long process for Android, iOS, OSX and Linux.
Or I can just make a web application that's slightly slower. The decision was super simple for me.
F* native development of UIs, it's stuck, everyone in it think it's fine - it probably is if it's all you do - but what matters a lot of the time is the sum of development cost across all supported platforms. shudder That means it's especially horrible if it's just you developing something, the chance that a single developer could support all of the most used platforms (Win, Linux, OSX, Android, iOS) is so unlikely due to the time required to learn just a single one of those platforms.
This is so extremely wrong it's not even funny any more. WS_CLIPCHILDREN and WS_CLIPSIBLINGS are the key here. Of course, many people don't understand them (eventhough it's not hard and the Petzold came out, what, 25 years ago?) but win32 is very well understood by now and it's trivial to make extremely fast (by today's standards) UI's with it, and relatively easily, too.