Edit: Today I learned that UTC is an actual real thing and not just a setting I scroll past on my computer 😅.
They also complicate things.
It made more sense back before we had electric lighting and when everyone lived by the rising and setting of the sun. Now it doesn’t seem to really matter.
Obviously, the whole world deciding where to start the time would be nigh impossible but it could be like: starting at this date, on the first day of the year, what ever point is farthest away from the sun is 00:00 from henceforth.
And then people just adapted to what that meant for their particular area. Somebody’s morning might be 13:00!
Imagine if the whole world was on some global time schedule.
Edit: From my comment below
Look at the earth from a top down perspective. It’s a pie. With 12 or 24 slices depending on the granularity. A clock, basically. It would take the same amount of energy to learn which slice of earth is lined up towards the sun for each hour as would be to learn anything else in elementary school.
After which, for the rest of your life you’d have an intuitive grasp of where earth is in its rotation and what “time” it would be for any place in the world.
So I agree. like you would know its 1am in another place when it was 1am for you. Thing is you would have no recollection of what was a reasonable hour for outher places. when you go see what the local time is in a place for your time you know if its a reasonable or unreasonable hour by where the sun will be there. Everyone knows 1am is an ungodly hour.