I have sleep phase disorder/insomnia/night owl so napping from time to time is just par for the course if I have had to force myself up for something early.
But I could easily operate on a 20hour day and sleep for 12 hours+ lol. I'm definitely not normal in this respect. My mind is very active while asleep so I don't even necessarily consider it a waste of time either, just processing gooseberry fool.
Anybody who has sensory processing disorder of some description or chronic fatigue will usually nap and yes you're often better off than just forcing yourself to do things barely conscious.
Also a nap doesn't have to be actually sleeping, it can be meditation or sensory deprivation too AKA resting your eyes.
A good nap is learning to transition from day dreaming into lucid dreaming and then realising you're nodding off, and then either doing that repeatedly or getting up.
Einstein's technique of holding a pencil or pen or whatever between your fingers and when your muscles relax enough that you drop the pen and this realisation wakes you up, that is how you're supposed to nap for cognitive or problem solving benefits.
Napping for longer is probably a snooze or a short sleep. There are demonstrable benefits to resting the mind and body too during the day but if you do struggle to get to sleep at all you should probably avoid it. For instance when my routine was "pretty good" (say around midnight to 9:30am, but more typically 1 to 2am until 9:30 so not quite enough) I would meditate for an hour around to 1 to 2pm or thereabouts, which might include a nap once relaxed. I would then work or go about my day until a slightly later time than "normal" say 7 to 7:30pm. We eat late at 8pm and I'll go to bed anytime 9pm to past midnight depending on what I need to catch up on or do that isn't work.
Myself I will generally only nap if I've had less than 7-9hrs sleep, or more generally speaking under 9hrs as I do need more sleep than average. I can operate on about 4hrs sleep but either only for a very short period or not very well without a nap (e.g. nap on a train/plane to get somewhere before it's super late in that timezone).
Weirdly I find that if I get up super early for me (say 5-8:30am) I can stay awake for a very long time which overall means I won't get enough sleep the following evening. So it goes against the idea that just getting up earlier is necessarily a good idea, because I can then stay awake until either as late, or even later than usual. I'm not really sure why this happens - I think my body has some kind of ability when forced to run on adrenaline for long periods of time, probably caused by growing up going to school/college with little sleep (which itself probably began with childhood nightmares - it's bad enough to be in my record at 5 years old) and then having a lot of evening activities I wanted to do.
In bed I'm not necessarily sleeping at all either, I wake up and think at night or I listen to the radio/news/podcasts before getting up. So I could do 12 hours up and 12hrs down, or 16hrs up and a nap and strangely with less sleep 16-20 hours and then a long sleep.
It's all over the place and extraordinary hard to control. It phases in and out hence sleep phase disorder. Not so much out of phase but phasing in terms of length of sleep, need for sleep, and sustained activity during the day. Could work intensively for a few hours, break, then another few hours, maybe even another break and more work (maybe of a different kind) - break may include nap or deprivation or distraction / zen focus stuff. Could work not intensively for 12-16hrs and sleep relatively normally, or might work intensively for 10-12 hours and basically not sleep at all. I've done more.
Rarely ever work intensively for more than 6-8hrs but may do so and then do no work or nothing related or 1 or 2 entire days. Easily slept entire days but that's probably if I'm ill like anyone else.
My circadian rhythm is a total mystery. I can only maintain one with medication, sleep tea infusions, rigid routines/patterns, distractions from thoughts which seems frankly too much effort sometimes. I just do stuff on time one way or another and manage my own schedule, who cares as long as gooseberry fool is done.
Napping is just a tool really and it's probably more useful if you have some kind of sleep disorder, cognitive processing difference or fatigue caused by a more physical ailment.
If you don't need to nap, you're probably fortunate because circadian rhythm I strongly disagree is inherent to everyone and can vary enormously but also be kind of traumatic in that it is extraordinarily hard to manage.
Wikipedia has an observation I think is interesting:
The diagnostic criteria for delayed sleep phase disorder are:
An intractable delay in the phase of the major sleep period occurs in relation to the desired clock time, as evidenced by a chronic or recurrent (for at least three months) complaint of inability to fall asleep at a desired conventional clock time together with the inability to awaken at a desired and socially acceptable time.
When not required to maintain a strict schedule, patients exhibit improved sleep quality and duration for their age and maintain a delayed phase of entrainment to local time.
Patients have little or no reported difficulty in maintaining sleep once sleep has begun.
Patients have a relatively severe to absolute inability to advance the sleep phase to earlier hours by enforcing conventional sleep and wake times.
Sleep–wake logs and/or actigraphy monitoring for at least two weeks document a consistent habitual pattern of sleep onsets, usually later than 2 am, and lengthy sleeps.
Occasional noncircadian days may occur (i.e., sleep is "skipped" for an entire day and night plus some portion of the following day), followed by a sleep period lasting 12 to 18 hours.
The symptoms do not meet the criteria for any other sleep disorder causing inability to initiate sleep or excessive sleepiness.
If one of the following laboratory methods is used, it must demonstrate a significant delay in the timing of the habitual sleep period: 1) 24-hour polysomnographic monitoring (or two consecutive nights of polysomnography and an intervening multiple sleep latency test), 2) Continuous temperature monitoring showing that the time of the absolute temperature nadir is delayed into the second half of the habitual (delayed) sleep episode.
If you have better sleep quality (a major quality of life, immune and longevity factor), and more of it, but that's slightly incongruous with your environment (which seams to be what entrainment means) I don't see why it's a even a disorder.
Part of the whole 9-5 bollocks. If you nap, it's probably a symptom of 9-5. My partner has chronic fatigue from EDS and works gets up 6:30am, works around 8am to 4pm and has to nap every single day. Don't feel bad about and don't try it because someone told you it's a good idea either. Whatever works for you.
The only thing I'd say is an awful idea is napping almost immediately after getting up or right before you go to bed. Otherwise, whatever. If your body needs rest, rest. Humans are weirdly obsessed with regimenting such things.