This is one of the cases where ML methods seem appropriate.
My world is pretty fine, as I don't play games on servers, without active admin/mods that kick and ban people who obviously cheat.
ML solutions can maybe help here, but I believe they can reliable detect cheats, without banning also lucky or skilled players, once I see it.
Its okay if you havent played an online game in 20 years mate
These players aren't using aimbot / triggerbot (or if they are, they don't understand the gunplay and try to shoot while running), and may not even understand wall penetration, so their reaction times wouldn't look abnormal at all. From the data, they would likely have below average reaction times still.
Even though they are not performing well, their presence still massively alters the gameplay for legitimate players. For one, lurking becomes a pointless endeavor. You're better off rushing wildly than attempting any sort of stealth.