Fortnite has a decent anticheat, which also runs in Kernel. The skills to evade a solely usermode monitor isn't that hard, since you can literally just watch api calls and defend against some memory forensics. This is made harder for the cheat dev due to things like Discord running dynamic code, which looks EXACTLY like shellcode/cheat payload. Especially in a world with limited customer support, and even more limited on anyone who can help, false bans are a big concern.

DKOM(reading/modifying kernel structures directly) is alot harder to detect, and also alot more undocumented. To the point it takes someone in the field to make a cheat and bypass, vs someone with a decent level of application dev experience. And there's not many Kernel developers, and there's also such a limited amount of forensic/malware analysts that can code anything beyond powershell.

I think Fortnite uses a projectile bullet model while Call of Duty is all hitscan, but I could be mistaken. It’s been years since I played a CoD game.

> It is so obvious when someone is cheating.

It is not always very obvious, at least on CSGO... there are some experienced/smart cheaters.