VCL is also quite good, in spite of how things went for Delphi and C++ Builder.
Nothing prevents you to use WPF/UWP with visual designer and code-behind, just like Forms.
Where WPF/UWL loose in simplicity is when you want to start customizing L&F or use the standard DataGrid.
I'll admit though that the only IDE I've used that I like as much as Delphi 6 is Intellij.
Not at all, WPF is like having a monoid in the category of endofunctors for UI programming.
Its concepts of UI Lego style building blocks, with templates, commands, mvvm, multi-binding, storyboards..., might be hard to grasp if one is happy with plain code-behind snippets, but once one gets it, it is quite powerful way to write large scale UIs.
Takeaway: I will start using WPF right after I get a solid grasp on category theory. That will happen "very soon".
The only reason I stay away is because of the performance issues, and the opaque ways in which performance degrades.