The actual real benefit of 5G for me is beating very congested LTE towers at peak times. There are a lot of spots where the 4G mast (especially on LTE800) is completely congested, but 5G is much* better, though definitely starting to see 5G congestion in places now.
In time as people upgrade their phones the balance should shift then, with the 4G spectrum becoming less congested. Personally I don't find the speed increase of 5G to be a need as I never found 4G to be slow. I'll be quite content to lock to the 4G bands if they open up more.
No, because 5G at the moment combines both 4G+5G carriers together. This also seems to reduce performance of 5G on heavily loaded 4G cells (probably ACK packets getting delayed if it goes via the 4G upstream is my guess, but not sure).
