Changing a global time system is not a trivial task.

We’re still using a calendar developed over 400 years ago and just making minor tweaks. Without some central global authority, change is unlikely. And even with that, it would be extraordinary disruptive.

The middle for the day, on our time keeping devices, being light outside goes all the way back to the first sundials over 3,000 years ago.

Small and regular maintenance is more realistic than expecting a complete overhaul of timekeeping at some point when are lack of maintenance becomes so problematic that the whole system needs to be thrown away.