I think local time would work pretty much the same with a single time zone.

Single time zone: You get to a new place and look up what time is good for breakfast here

Many time zones: You get to a new place and look up what time zone you’re in.

Either way you need to look up what the local time is. But with a single time zone, i think the breakfast time and work hours would be a bit better attuned to sunrise/sunset at your location.

To me, the main difference is more philosophical. I think it’d encourage a more global perspective.

Edit to add: it’s more of a pie in the sky wish. I dont think it would be worthwhile to actually remove time zones. It would be very expensive for not a lot of gain. In the same vein, I’d like to:

sort out our calendar (evenly sized months, dates corresponding to weekdays, and not have prime number of weekdays),

sort out our time units. Lets keep it all in the same base (not 24h days and 60min per hour)

transition to a base-12 numeric system. It’s just much more satisfying.

Lets just do a single time zone