Going with UTC doesn't work all that well.

Time zones give a rough idea of where the sun is and whether people are more likely to be asleep or not.

Like I know if I schedule a meeting at 8am in New York, that's 5am in California so I'm unlikely get people from California to attend. Or at least it's pretty rude of me to expect people in California to attend

If I schedule a meeting at 12 UTC - that gives no indication of where the sun is in New York or California (or anywhere).

The fact is people tend to do things with the sun is up and sleep when it's down. Time zones are a compromise so your clock is still kind of in sync with the sun while still being able to synchronize with larger areas.