Early and late are relative concepts. As others have pointed out, there's a variety in natural circadian rhythms, as well as preferences.

So to claim an approach other than your own is "absurdly wasteful" strikes me as just shallow and arrogant, and the reason we wound up with DST in the first place.

In my case, I struggle to do serious work outside of 10am-10pm. I wake at 7am because of my partner, but for the first three hours of every day, my brain hardly works. I have to fill my time with other things - exercise, reading, chores, and so on. If left to myself, I naturally go to sleep at midnight and wake at nine, and feel better for it.

With that said, even if we forget about that, what's early is defined by what we consider late.

If you have a teenager who needs 9+ hours of sleep, and they cannot go to sleep before 11pm (because we allow people to be noisy until at least that late), then 7 is quite early, yes.