We're most of the way there with the switch to web apps and their native wrappers, even Microsoft isn't using their own UI toolkits anymore. The only segments

We're most of the way there with the switch to web apps and their native wrappers, even Microsoft isn't using their own UI toolkits anymore. The only segments left targeting Windows as a platform are games, replacements/extensions to the OS tools, and a bunch of legacy .NET LOB apps. And since the Steam Deck and clones, Wine/Proton are (very) slowly becoming the actual target for games rather than Windows.