> But today... aren't they, at least as a first-order approximation? (With some further adjustments to avoid antialiasing artifacts, desired sharpness, and so forth.)

It still depends on what you’re using them for. Image that will be rendered straight to a webpage? Yeah, it’s probably a fine first order approximation. But that’s not the only context that gets rendered on a modern screen.

Say you’re using it for 3-d scenes. Yeah you absolutely should pay attention to what the paper says about footprint and sampling and filtering because, when you render it onto the screen, all of the processing steps between pixels on a texture to pixels on a screen require awareness of pixel footprint.