Could we just rest instead? The answer is no, because when we do nothing for a long time the disorder in our body and mind gradually increases and we loose our wellness. This is fundamental scientific fact established in the natural philosophy (physics) and applied to all isolated systems including people when they do nothing. It states that the entropy of an isolated system can only increase with time. In plain English entropy means disorder and isolate system means the system that just rest and do nothing and the whole statement means that if we just do nothing we eventually get a disorder. You may find the real life samples in the pages about intellectual and physical wellness exercises.
If we do nothing the disorder stops to increase only when it becomes complete. Guess what does it mean? The science answers that the entropy can only be a constant if the system is in the highest possible state of disorder, such as a gas. You probably would not like to become a gas.
We see that even if we are affluent and may allow ourselves the inactivity, we should avoid it because of the health safety considerations. We have to do a kind of exercises to maintain our wellness. As wrote Lewis Carroll, "Now, here, you see, it takes all the running you can do, to keep in the same place".
The good news is that the "exercises" to keep up the wellness are often easy and you may like them. For example, it may be the mixing with people or to have a massage.
The bad news is that the people have no reliable sense of time and nothing in our body or mind warns us that it's time to do these "exercises" before we get the disorder. Another problem is that we should move with time in all the six important dimensions of the wellness wheel.
We see that we need a kind of external wellness monitor. However it is not the same as the health monitors that warns us when it is too late and something has already got the disorder in our body or mind. We rather need the monitor that warns us when we have dangerously neglected the corresponding wellness wheel dimension, the monitor that do it long time before we loose our wellness and become ill. We need the wellness keeping monitor that is flexible enough to understand that we cannot always be on schedule, do the exercises in time and in full volume. Nevertheless it should show, which of the six wellness dimensions are neglected for the dangerously long time. It should show the current priorities.