Most of these issues exist on other platforms as well. Try running a QT or GTK app in Mac, or an opposing widget kit app on Gnome or KDE.
Things have certainly gotten better (similar to HiDPI support, multi-monitor, etc) as developers have standardized or learned the tools, but an individual app can choose to do it’s own bespoke rendering on any platform.
Fair, it's not a windows issue. I only use windows, so I've only experienced it on windows and I didn't want to overstate - but obviously that was poor wording on my part.
Most of these issues exist on other platforms as well. Try running a QT or GTK app in Mac, or an opposing widget kit app on Gnome or KDE.
Things have certainly gotten better (similar to HiDPI support, multi-monitor, etc) as developers have standardized or learned the tools, but an individual app can choose to do it’s own bespoke rendering on any platform.