1. People who never collaborate globally/cross TZ vastly outnumber those who do. And the people who do can already use UTC right now.
2. Making everyone in the world to use UTC is going to make everything less convenient for everyone who lives a few hours away from the UTC TZ (i.e., most of the world). Because in UTC many of their daily events are going to span 2 dates/weekdays.
The world has changed and we often collaborate globally.
I remember we had todo this zoom meeting.
- 1 guy from USA - 1 guy from Europe - 1 guy from East Africa - 1 guy from Singapore
It was extremely difficult to schedule a meeting off head.
When the it was okay for the guy from East Africa to meet it was like 5 am in Singapore.
Even if you successfully organise the meeting.
The organizer having to translate all times to the respective time zones of the audience is just so painful.
Okay now we have Calendly a tool we have to sign up for. But conversations of scheduling would be much easier if everyone in the world used UTC