There’s also evolutionary bias for why natural selection would have favoured staggered sleep schedules - in a group setting this would have allowed different people to stay alert at different times during the night and thereby increasing the chances of survival of the entire group.
Irrespective of all of this - it fucking doesn’t matter. If some people say they struggle to get up early and are sincere about it, it makes sense to provide very basic accommodations. For example, what’s the harm in having meetings only after 9pm? Also don’t schedule meetings after 3pm so those who are the morning types can wind down and get home? We make all sorts of reasonable accommodations for food preferences, religious beliefs, …etc. If some people are more productive during certain hours, it fucking makes good business sense to let them work during their best hours - within reasonable limits.
I can only recommend people to read Why We Sleep by Matthew Walker for the health and economic damage we do this society in the name of perfect adherence.
(I have an ADHD diagnosis but looking at the effects of poor sleep sometimes I wonder if I really have ADHD or if it’s just the poor sleep that’s been fucking with me all my life)