They've done this sort of thing with app installers(setup.exe, click once, appv, msi, msix) and UI frameworks(win32, mfc, wpf, winui 2, winui 3). It's like the teams responsible for their respective product keep starting over with a shiny new way of doing things every couple of years to achieve the 'perfect' installer/ui framework or anything else for that matter. Infact W11 felt like a way of 'restarting' W10 without building a whole new OS.
Atleast with W11 they're actively updating old things rather than introducing new ones, I did not have a lot of hope when it first came out, but they have gotten my hopes up since the release for sure. I just hope they stick with winui 3 and see it through.