How come after so many decades Steinberg still hasn't implemented GUI Fullscreen mode?

Title says it. I’m talking about the GUI fullscreen mode (think Ableton Live, Pro Tools, Studio One, Logic, Bitwig, Reaper, Fairlight (Resolve), etc) in MacOS. In Nuendo /Cubase Mac, only the video player goes true full screen. I was wondering if there is a major roadblock preventing its implementation throughout the GUI.