I think at a base level it was
revolutionary, in the sense that it very much depicted an "ideal future" where humanity's contemporary differences had long been forgotten (this was hard-wired into the concept, even as depicted in the original 1964 pilot episode). But in terms of television production
I'm not quite as convinced. There were many tv series' of the time that had a cast that was at least as racially mixed as Trek's was, it wasn't as uncommon as people have sometimes made it out to be. And let's be honest: at the end of the day, the secondary player's roles weren't really
all that progressive. Uhura is basically a telephone receptionist, Sulu does very little more than fill a seat on the bridge, and so on.
Tops marks for the concept. Less so the execution at times.