Square pixels are a filter just as much as CRT filters are. In fact, they distort the image even more. Even leaving aside all the things that just don’t work right in square pixel land, turning every pixel into a square messes up the aspect ratio of a lot of old consoles. Everything ends up squished and stretched because it wasn’t designed for square pixels. You can call that distorted funhouse mirror version of old video game art “crisp” if you want, but in reality it’s just the cheapest and worst filter.