It will be no news to anyone that teenage brains work differently. The part of their brain that controls impulses - the pre-frontal cortex, just above the eyebrows - isn't fully developed and this largely explains the tendency for all of us to not always make the best short-term decisions as teens. For example, poor decision-making and planning about sleep.
But the main problem is that, as teenagers, our brains also work differently - particularly with regards to sleep.
Adolescent bodies tend to biologically wind down slower and, as a result, tend to not feel tired until later in the evening, naturally setting them up for more of an "owl" late-night circadian rhythm. The chemical culprit is melatonin, the hormone the body produces to bring on sleep.
Of course, individual results may vary. Not every teenager slips into this pattern, because the impacts arrive on a background individual pattern of sleep that, for some, means it may leave them still able to manage a reasonable early start.
However, what doesn't help is - as you've wisely spotted - turning it into a battleground - the natural human tendency is to dig one's toes in - or, in this case, pull the duvet over one's head!
A more useful approach is to provide more information, support problem-solving and allow for natural consequences.
This can be misunderstood as leaving it up to them, but actually it's much more active than that, because before you step back, you need to make sure they have all the information they need to solve the problem.
So, talk with them about the fact they're having to work against their body and help them to understand what helps you wind down - less light, eating earlier, not staring at a device while trying to sleep, regular bedtimes and setting an alarm. Alert them to the dangers of oversleeping in the weekends, thereby blowing any schedule out of the water. Help them make plans to avoid that.
On the flip side, allow them to find motivation to work on the problem by allowing for the natural consequences of sleeping in and being late for school happen. But importantly, let them know you're doing this before you make the change and that if they need any help, they just need to ask.
By all means try to wake them up but, if they don't rouse, don't nag. Remind them of the consequences - whatever these might be at their particular school - and then walk away, whistling a happy tune.
Like all of parenting, it's give and take. You may have to step back in again a bit more forcefully if getting themselves back on track proves to be too much of a challenge. You may even need to talk with your GP if you feel sleep is really taking over, and getting to sleep starts to interfere beyond what you, or your teen, can manage.
But the task of adolescence is gradually becoming an adult. And learning responsibility requires parents letting them take more control, albeit with training wheels at first.