Uncle Steve is the same number of hours ahead that he has always been, and that's a thing that could be looked up just as easily as finding his time zone. I think the author is greatly exaggerating the degree to which time zones solve any of the problems mentioned. Uncle Steve might be on a different sleep schedule from me, regardless of whether or not he's in a different time zone.

Days of the week definitely become interesting in a global UTC system, but noon used to literally mean "the sun is at it's highest point". I suspect that people would grumble for a year or two and then forget that another system ever existed.

Before UTC4ALL: is UB awake? what time zone is UB in? idk, what zone is Melbourne? +11? uh... carry the one... 6:25, maybe a bit early, let's try in an hour[1].

After: is UB awake? he said gets up at 13:30, so call in a couple hours.

You want to call someone, but you don't know when they're available? Maybe you should ask them, so they can tell you it's 13:30 to 4:00, with zero "is that my time or your time" worries. Or check your shared location-aware calendar, which already handles both cases equally well.

How often do you do several-thousand-mile phone calls without knowing anything about the recipient's schedule? Where I come from that's gonna be rude, send an async message instead.

1: yes, the math/calculated time is wrong. on purpose. as an example.

1 kilosecond: about 17 minutes

1 megasecond: about 12 days

1 gigasecond: about 32 years

"Oh man, it's been a hot megasecond since we last spoke!" Said everyone, in my worst nightmares.

Better than guessing what timezone the region picked when it spans multiple natural time zones, and whether they do or don't have time changes.