From my brief experience working on 5G, I learned that most of the advantage of 5G is for the provider – not the phone-using customer. There are new higher-bandwidth sections of the spectrum that can be used by 5G, but those are power hungry and short distance only. The main part of the 5G bands are just the 4G bands with an updated protocol, so they’ll have roughly the same speed.
Also, since 4G has to coexist with 5G, neither technology can use 100% of the bands they could, which prevents them from reaching maximum bandwidth.