The Problem With Kernel-Mode Anti-Cheat Software [ML B-Side]

Nobody likes cheaters, especially in video games: we play games to have fun, and nothing hurts the joy of playing a good game more than losing to a cheater. That is why EA is not the only publisher to implement kernel-mode anti-cheat software in their games: League of Legends and Valorant, for example, use similar software. Yet some people warn that installing such kernel-level systems is extremely dangerous. So, what's the problem with kernel-mode anti-cheat software?