Wasn't it a bastardized watered down version that cached the elements behind it and still gave a performance hit?

They seem to be running into the same issues and didn't take the learned lessons with them

It was still ugly, but it did kinda work because it only affected the window chrome, and it could be set to opaque with an easy-to-find setting.

On macOS the checkbox for "Reduce transparency" is hidden away in the Accessibility settings panel which is the last place I'd look for configuring the desktop theme.

Many good settings are ‘hidden’ in Accessibility, notably to increase contrast, differentiate without colour, etc.

The wonderful ability to control music playback on your Mac? It’s in Accessibility on iOS.

Thinks like Reachability, Shake to Undo, and Require Attention for Face ID are all accessibility features.

Evidently, Accessibility is the new Advanced Settings for Apple, and anything goes in there. I’d argue many of these should be On by default.