Adding HTML to the GUI coding is re-inveting the wheel. There are native toolkits for UI, there are crossplatform UI libraries for a reason. They work, they are fast.
No need to add extra layers on top of those.
No need to add extra layers on top of those.
Even Java's AWT, which came at the tail end of this and pretty much only targeted UI functionality that was common between different UI systems, could create desktop apps that were and are much more usable than the inconsistent web-inspired desktop apps we deal with today.
Issue comes when the whole operating system would be run on top of some XML thing...