Will UWP ever be able to replace every kind of desktop application?

I found this ridiculously in-depth explanation of the limitations UWP faces vs win32 applications in respect to system access.

http://stackoverflow.com/questions/36286806/uwp-limitations-in-desktop-apps/36288769

Any ideas on what important applications require the advanced system access UWP doesn't supply? Do you think UWP will evolve and become more powerful? The way we use computers is changing so fast. It's very hard to imagine where Windows is headed.

Edit: I figure this is relevant enough to r/windowsphone since the maturity of windows on phones hinges on the success of the UWP ecosystem and the phones' eventual parity with the full windows experience.