For the most part, yes? Sure, the very first time I talk to someone in a new time zone I have to look it up, but IME with working with globally distributed teams you get used real fast to thinking "China is at -9 (+ 1 day)" or "Amsterdam is at +8".
That doesn't change without timezones, you only have to remember a slightly different fact (at which time does their workday start). No real benefit there to keeping timezones.
The biggest advantage of getting rid of timezones is when an absolute point in time is mentioned, e.g. the start of an event. It's so annoying when the start date for some global event is announced and they only include a local time in some obscure timezone.
If you're going to live-stream an event for the whole planet to see, use UTC. It's especially baffling that organisations such as SpaceX or NASA use local time instead of UTC. You'd think that anyone dealing with things in orbit would use UTC.
Cool. You already have the knowledge you need to figure out what party of the day it is in another timezone. Now when you say let's meet at 10, you don't have to figure out which 10 you are meeting at.
