You’ll basically have timezones either way, there’s just two ways of doing it.
If we all used UTC, then businesses would need to change what time they opened depending on their location. Ex: Best Buy opening at 12 noon on the US west coast, and 3pm on the east coast. Locations inbetween would have different opening times. So we would get the noon zone, 1pm zone, 2pm zone, and 3pm zone. All nation wide businesses with standard open/close times would effectively follow the same pattern, and it would be best if they all coordinated on where those zones occured. So then we would get new timezones, they’d just be slightly different in how they functioned.