Yeah, exactly right. Before industrialization, you’d simply wake up with the sun. If you ever go camping or on long outdoor trips, you might notice your schedule becomes suddenly much more aligned with sunrise. Mine does, anyway.
> I’d rather go to sleep earlier so that the 4am feels like 5am
That’s totally reasonable, but hard to achieve alone. We agree on the workday schedule norms together as a society. Flexibility would be nice, but much of industry depends on schedules and people physically working together, so they don’t (yet) have ways to relax the rigid schedules. Another thing to consider is the summer nighttime is less than 4 hours long (not counting any twilight at all). That means if you sleep 8 hours, you do have to choose which end to cut into.
I expect less rigid working styles to increase in popularity for some professions, but there will always be situations where people want to do things at the same time, which is substantially easier if they can agree about what time it is.