No we like photos with blur in the background. We prefer such photography. So who’s to say the faux surface fails?

Again we need evidence based measurements which the entire UX field lacks. It’s just a bunch of made up concepts strung together with little scientific research.

The blur is depth dependent, not an uniform filter.

And there’s a lot of research regarding UX, under the term Human-Computer Interaction. The thing is that it easily converge to something like Win 2000, macOS Leopard.

A photo isn’t an interactive interface so there’s entirely different perception tasks involved in parsing it. We like a lot of things in photos that are horrible for UI design — and vice versa.

But this also gets into another gray area where looking at a design for a UI != using said design to perform important tasks. Hence why prototyping and user tests often run counter to “pretty” interfaces.