Umm… we are already using GMT/UTC, it’s just that we adjust it based on offsets because long ago before clocks we used sundials and high noon was just the time when the sun was at its highest.
The problem with adjusting the time locally is that it leads to all kinds of problems. 9am… where?
This has nothing to do with politics. No country is trying to change the 0:00 time.
I hope you understand now. Let me know if you don’t and I’ll elaborate.