Unlikely. 5G hit the wall on UWB (Ultra Wide Band; 10-100GHz) because geniuses who were doing marketing for its transfer speeds did not realized that such high frequencies are disrupted with minimal amount conductive material in the air - so surprise surprise, 5G UWB does not work when you are behind a wall, it does not work when your big head full of water is in the way of BTS and most perplexing for common folk, it does not work behind a glass because regular glass is full of iron - so forget on 5G UWB on a train, tram or bus, unless somebody put mini BTS inside the vehicle.
So 5G for most folks is just marginally better LTE and that's about it. Any higher frequencies like 6G (30GHZ~3THz) or 7G (???) won't achieve much of anything outside of laboratory, because they will hit exactly same walls like 5G UWB.
Ultra Wide Band (UWB) has nothing to do with Extremely High Frequency (mmWave). UWB is usually in the 6-8.5 GHz band but with 500 MHz wide frequency, while mmWave is above 24 GHz.
There was full team that found out that did the test that 26ghz doesn't work IRL. It didn't even work across a street corner. But they were ignored in favour of some well, career pushers.
In india, jio is using 26ghz for wifi now instead. It's a service called airfiber. This don't even use any 5G. It's a weird custom hybrid solution where all the frames are wifi. Density here means that it's feasible to put the receiver on the rooftop of apartment buildings wherever you can get LoS. So in some sense it's been salvaged and those bands are actually being used. It's a fairly popular service.
URLL failed because it's main immediate usecase was supposed to be vehicle to vehicle comms. And auto didn't want telcos middlemanning there. But there is still hope here.
Well mmWave was never for large areas. It's for ultra high density like in stadiums with 100k people. You know those cases where current networks are completely unusable because they saturate.
Its extremely limited range and penetration is a benefit there because you can put up thousands of cells without them interfering with each other.
It was also meant for offices as a managed WiFi replacement. Stuff like that. In this vision every laptop would have 5G built in and could work anywhere. It just didn't take off because of the chicken egg problem. Not many phones with mmWave. Not many providers with it.
The speeds thing was just marketing BS as usual but mmWave did have benefits in niche scenarios.