You seem to be confusing the set of standards called 5G and the high-frequency mmWave bands that are an option part of it. mmWave makes little sense except in special areas and that's also why there's very very limited deployements of it. On 5G as a whole? Lots of network-level architecture and signalling improvements still, but depends on NSA/SA, used bands, implementation quality, end-user equipment bugginess, etc.