Apple used to insist that different types of devices require different UI principles. This seems all the more true for a transparent device that you wear on your face while moving around trying not to bump into physical objects.
But we'll see. Perhaps the right level of transparency is situational. If you sit down with iGlasses using them as a screen you might want to reduce transparency while increasing it when you're moving around outdoors. Adjusting transparency could become as routine as adjusting audio volume.
I'm still on 18.x thats insecure by now and switching to Asahi as soon as something breaks.