"We could even decouple our sense of time from the Sun entirely, to create a single world time zone in which different countries see the Sun overhead at different times of day or night"

Interesting thought but would be impossible to implement in a world where almost everything is coupled to time, which in its turn is coupled to the sun. I can't even imagine being in a zone where 12pm is at night 😅

If GPS (on which most systems base their time) already ignores the leap second, this seems like a logical step. Imagine having to sync 2 systems where one takes the leap second into consideration and the other ignores it. Seems like a very unnecessary hurdle.