Pushing yourself doesn't always make you stronger, for many people it can do the opposite. Harm and challenge is not an inherent good. There is the common saying that an ounce of prevention is worth a pound of cure, and that applies to rest too.
This can be seen clearly in many of the different things we do while resting, like organizing the spaces we live in. In the moment it might be much faster to look through that mess instead of cleaning it up, but eventually it will cost far more time overall. If we are living paycheck to paycheck though, we might not be able to sacrifice that time.
This is a perfect argument against things like wages in any system though. I know many people say we need “incentives to work” or to “give resources to groups that do the most work, so that they can do more”, but that is by far the wrong way to look at it. Convincing someone to work too hard now can cause them to do less in the future, no matter how many incentives and threats you add. Rewarding people for doing more in the moment just means you are systematically rewarding people who just look through that mess more, instead of those that clean it up. If you do that enough, give them the energy to expand and make more of that form of organization enough, eventually you won’t achieve anything but collapse.
Without time to rest we will achieve nothing, and punishing people for resting will only be counter-productive.
Metrics from a distant observer will never replace the workers there in the moment.