But if you need rate there's this: JOB_OBJECT_ CPU_RATE_CONTROL_MIN_MAX_RATE https://learn.microsoft.com/en-us/windows/win32/api/winnt/ns...

As far as the verbiage goes -- "doesn't exhaust" means "uses less than the full amount available". Given that "total CPU time" isn't something you can run out of, "doesn't exhaust CPU" can only mean "uses less CPU than is currently available", i.e. "utilizes < 100% of the CPU", i.e. throttling.

As a practical matter, pretty much ~no user wants to kill a program after N seconds, and ~no program can limit itself to N seconds of work, either. People just want their CPU to have bandwidth to do other work, avoid heating up, etc. So unless you have a strong reason to believe otherwise, it's fair to assume people want to limit CPU utilization, not total CPU time.

This is exactly how the web and cloud FaaS like AWS Lambda does it, so I don't think it's right to say nobody wants this. Runaway code does need to be killed.