That’s not correct. See physically based rendering (pbr book) chapter 8.
Non-antialiasing is just taking fewer samples and not attenuating the aliasing artifact band with a filter.
A gui is more complex. Most graphics are collections of blocks. But then if you do any effects like filling a bezier curve or shadow you are back to the point sampling model.
If you used a camera or a GUI to generate your pixels, they are not point samples.