I think this is like machine maintenance.

Take a delivery truck. Regular maintenance detects, and prevents breakdowns during deliveries. EG, oil changes, lubing, brake pad changes, etc.

Scheduled repairs are far cheaper, and take less time than unannounced repairs.

If the truck breaks down during deliveries, the repairs are still needed, may be more severe.

It also require loads of extra work, a replacement truck must show up and offload deliveries, a tow truck dispatched, someone had to organize this, customers upset and called, etc, etc.

As you say, humans are the same. Reduced sleep and leisure time (scheduled maintenance)?

Well, it's far more work to deal with in the long run. It takes more maintenance to recover from a lack of it.