Actually, no, that's incorrect.

You're thinking of wallhacks or wallhacks+aimbot

Aimbots only aim at things you can see, it's one of their main features. That way you won't snap into someone's head through a wall which would make everyone know you're hacking and get you banned.

I'm no expert here but surely aimhacking originally implied wallhacking? The alternative requires doing actual image analysis in realtime, which AFAIK has only become feasible in the last decade and is way more processor-intensive than just reading coordinates in memory and doing some trig to adjust your aim height. Maybe this is selection bias talking, but I see plenty of videos of cheaters who are obviously just snapping to heads through walls.

You don't actually need image analysis. There are tricks you can use to decide if an enemy is visible or not without it - obviously the game itself does it already to decide if it should draw the enemies to begin with :)

Also yes these were invented a long time ago because people got caught snapping through the wall when CS servers started recording demos.

Since you can check in memory where the enemies head is, you can obviously also check if theres a wall inbetween. Cheats for video games have had humanizing/cloaking forever.

Modern FPSes like CS:GO don't even send you data your client can't see/hear, so wall hacks are effectively near-impossible.

That's not true. They don't send data in _regions_ your client can't see/hear, but if an enemy is for example close to a corner or on the other side of a door, you can have a wallhack see that as the client is still receiving it.

Thanks to latency & the realities of the internet, the server has to bias towards sending data the client can't strictly see/hear at that exact moment, but potentially _could_ see if they move. Which is enough to give a wallhacker a meaningful advantage still.

But what you can't do anymore is see where all the enemies are going at the start of the round and run to the weaker part of the map or whatever. So reduced effectiveness, but still a thing.

While that's true, being able to see any enemy that you could theoretically hear at all is huge.