If anything, a stupid simple method of server-side aimbot detection would simply be to create phantom player locations. Like randomly generate fake player locations without any character models. Invisible to regular players, but anyone who snaps to that fake location just got busted for aimbotting.

That does not work at all for pixel detection bots. They're not reading game information; they're monitoring the video output. Either directly from the HDMI output or by just using image capture on the monitor. You never have to touch the game, or even the machine the game is running on. There is absolutely nothing to detect!

You'd have to rely on seeing them visually to identify the cheaters. Which is next to impossible if they are good enough to hide it.