I just mentioned the tabs disappearing is better solved than in Apollo, didn’t say that was mandatory as per guidelines.
As for the frosted glass effect it is UI as well as UX, as UI contributes to the UX. If you personally don’t like it, that’s your thing. It’s especially nice to have the content scroll under the bars, it makes the static boring monotone footers and headers come to life and gives you the illusion of a bigger screen. Take the latest Netflix design on iOS for example. The header is huge, but the video poster moves so nicely under them. All the Apple iOS apps have this effect. And a lot of Apple users care
Dude, you can’t eat grass and expect to get B12.