Because we had that. The reason GMT exists is because train stations in England all ran on different clocks. The train could leave at 11am and arrive at 10:55 at the next station because the clocks could be that far apart. And that was confusing so they said “hey you know what’s a good idea? Having a coordinated time!”
Going back to that would make things more confusing. You take it for granted that we all use the same calendar. Nobody signs your paycheck using the Chinese calendar, right? You likely agree that the US using the imperial system is silly because wouldn’t the world be in a better place if we all used metric. So why the resistance to this?
Huh?
We're arguing that timezones make sense and that keeping the world in a single timezone ("UTC everywhere") would not be a good option. You seemed to argue that if timezones hadn't already been invented then the idea of a local time would be insane. That's what I was replying to.
Going back to that would make things more confusing. You take it for granted that we all use the same calendar. Nobody signs your paycheck using the Chinese calendar, right? You likely agree that the US using the imperial system is silly because wouldn’t the world be in a better place if we all used metric. So why the resistance to this?