If you're rendering a videogame without antialiasing, they are.

If you used a camera or a GUI to generate your pixels, they are not point samples.

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.