WPF was abandoned at birth, it went years without any attention and then was superseded.

Apple has at least been consistent on UI frameworks.

I think you might have meant UWP.

WPF is still around and have been spruced up as of late.

UWP was the DOA Windows 8/8.1/10 app format that was super restrictive, strange to develop for, and non-portable. It's basically MS's equivalent of SwiftUI.

WPF was stamped out by lack of dogfooding = inability to inspire confidence, and then Microsoft spazzing out with that clusterfuck that was the Windows 8 "Metro" bullshit.

Back when I wanted WPF to succeed, Microsoft was barely using it in any of their own apps.

Apple has used SwiftUI in their OS more than MS/Windows did, and there's quite a few apps on the App Store that -seem- to be made with SwiftUI.