Well isn’t that okay? If you live in a big city your need to sleep of 8 hours is spread to a lot of people so people would just need to add few seconds of their sleep.

If you’re traveling away from civilization, that’s another story.

Hmm, your side effect also doesn’t specify the organism taking the sleep burden is a human so it can spread to other animals. By virtue this is a pretty useless side effect or even can be used as an explanation on how their powers work.