Mr Seeall is not seeing it all.
5Ghz WiFi is NOTHING to do with phones as such. It can be used by ANY WiFi device connected to the 5Ghz on your router, Smart TV, Fire Stick, etc etc.
The 5G (5th Generation) phone network is for suitably enabled phones with 5G SIM cards.
Which of course, could be configured as a 5Ghz hotspot. So then you get the 5Ghz WiFi via 5g phone network.