EDS, "Excessive Daytime Sleepiness", has become a thing, a real symptom.
I've been reading up on the topic. Supposedly EDS is a contributory cause for 20% of auto accidents. The list of causes of EDS is lengthy. It includes, of course, Obstructive Sleep Apnea which can reduce sleep efficiency.
In my view, EDS can often be easily dealt with with a brief power nap. I suspect many hard-working people do it but it's difficult to do in a public work space.
After-lunch naps are normal in many cultures, including in China where it is a legal right.
Is Napping Good or Bad for You? The Science Behind a Power Nap
The power of the 20 minute nap