It’s something that a lot of lip-service was paid to, but not a lot of action was taken toward. If the world in question wasn’t already capable of going to warp speed, democratic, and generally a lot like the idealized Earth with some minor quirks, the Federation just decided they weren’t important and pulled out the Prime Directive. Planets that were minor Federation members could be allowed to basically call into ruin, like Tasha Yar’s homeworld, and the Klingons and Romulans both basically had to force their culture into the same, “just like us but with a quirk” ideal when they were trying to get diplomacy going with the UFP.

Basically they talked a good game about being a united federation of worlds, but only federated with those who fit their echo-chamber.