system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:Why are programs allowed to use 100% CPU ?

Why doesn't the OS prevent any application from hogging the CPU ?
gpt
We bought the CPU to be used, not to sit idle.  If one program wants all of the CPU and no other programs want any, why would the program that wants it not be given it?

The CPU doesn't have inertia.  If someone else comes along and asks for CPU, it can be taken away from the first process in a tiny fraction of a second.