The difference is, on a projector I want the content to be blown up. That's the whole purpose. On the other hand, I want text on monitors to look like printed

The difference is, on a projector I want the content to be blown up. That's the whole purpose. On the other hand, I want text on monitors to look like printed out, and hung up. Real paper doesn't scale with viewing distance. Instead, there is foreshortening - stuff a bit further away looks smaller, but I know it is the same size. It doesn't mean all text should be the same size ever - on the contrary. If I sit further away, I want to choose a larger font size or greater magnification. All I want is, when dealing with physicality - stuff to print out, or stuff behind a touchscreen that pretends to be real - I want to be able to set a slider to "100%", and put a ruler or comparison document up to the screen, and have it match perfectly. I want stuff on dual monitors and large tablets to be the same size by default. I needed these features already several times this week: I printed out a document just to get a better impression of how the font size looks on paper. I also had a scan of an architectural drawing on milimeter paper (1cm = 1m), and wanted to compare it with a paper blueprint - if it was the same scale, I could just hold a ruler against it.