Suppose you want to schedule a phone call for two weeks from now with your colleague in Melbourne. That's currently kind of challenging. It's fairly easy to accidentally agree to an inconsistent time. What if that two weeks straddles a DST change in one country, but not the other?
In UTC world, you agree to a single time, and there's no confusion. To pick an appropriate time, just look up the range of business hours in Melbohrne, and intersect those hours with the business hours wherever you are.
I don't really see how your google or clock app examples are compelling. Just google "business hours in Melbourne", and then save those in an app or wherever if you think you'll want that information again soon.
> I can save those cities in my clock and swipe between them at any time.
If everyone used UTC, you could have just one clock, and turn it into a (possibly overlapping) pie chart - a different colour for each of your office's (approximate) business hours.The last week has been stupid, with UK and Europe already switching back to standard time with the US lagging on DST.
UTC Now! (Sent at 16:16 UTC)