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.
First off, that already exists with UTC.
Secondly, there is zero chance of getting the entire world to agree to stop using time zones at the same time. At best, it would complicate things even further by having some countries using time zones while others don’t.
Time zones provide helpful frames of reference. With few exceptions, 8am-6pm is roughly a standard day nearly everywhere. It is where most of the daylight occurs, when most people are working, when most businesses are open, etc. If you are traveling somewhere and have an appointment at 22:00, how do you figure out if that is in the morning or afternoon? What time would I make a dinner reservation for? When should I plan on sleeping?
What happens to Daylight Saving Time? I assume you would want that to go away as well? That brings up its own problems which is why DST is still a thing even though many people say they don’t want it.
It would likely end up with individual states and even cities creating their own “standard” work days, so instead of time zone covering an entire region, there would be a complicated patchwork of unofficial mini time zones.
If you travel far North during the Summer or Winter when the sun is either almost always up or down, how do you know when morning and night are? Do you have to look up the work schedule of local businesses?
Would it be possible to stop using time zones? Yes. Would it completely change the way most of the world has handled scheduling for multiple generations? Also yes. Would it even be beneficial in the first place? That is at best, debatable.