Except you are conflating "work in the daytime" with "work 9-5". There is absolutely nothing wrong with your sunlight hours where people work being from 1900-0300 rather than 0900 to 1700 hours.
If you made that switch everyone living in an area will get used to the times the sun rises and sets, and the normal work hours of the locale based off universal time rather than arbitrary regional timezones or DST. When you travel, you don't have to have migraines trying to manage the clocks, because your clock is always right. You would still have the same trouble adapting to another regional work cycle than you would now - you just remove the unnecessary burden of arbitrary timezones to make everyones sunrise happen at "roughly the same numerical time but never at the same actual time".
If you're not actually going to change the times that things happen then nothing stops you from using UTC already. The whole problem with daylight savings time isn't that you have to change your clock, it's that you have to change your schedule.
It would be excellent if everybody responded to daylight savings time by scheduling work to happen from 10-6 instead of 9-5, so that nothing actually changed but the clock. But that obviously only works if everybody does it.
If you made that switch everyone living in an area will get used to the times the sun rises and sets, and the normal work hours of the locale based off universal time rather than arbitrary regional timezones or DST. When you travel, you don't have to have migraines trying to manage the clocks, because your clock is always right. You would still have the same trouble adapting to another regional work cycle than you would now - you just remove the unnecessary burden of arbitrary timezones to make everyones sunrise happen at "roughly the same numerical time but never at the same actual time".