It's a double edged sword. A lot of system failures happen because every single thread winds up accidentally blocking on something that is never going to return

It's a double edged sword. A lot of system failures happen because every single thread winds up accidentally blocking on something that is never going to return for one reason or another. In such cases a timeout is able to unblock the threads. Maybe the developers collected lots of data and said p99 latency is X, so let's set the timeout X+alpha. If something takes drastically longer than most requests it's probably something going wrong. Maybe your latency was the 99.99999 and the timed you out. Or yeah the devs just guessed and guessed badly and the timeouts cause more problems than they solve.