1231asra

Somewhat true, but standards could assist developers with adequate test vectors, explanations and reminders why X or Y is important.

5G is a protocol upgrade.

You can upgrade 2G bands to 5G: massive coverage but without the shitty 2G protocols.

You can use 4G bands for 5G, and for 4G smartphones it will still look like 4G.

And finally, there's the possibility for low-range cells at very high frequencies. One possibility of many.

There is no need to re-build all the infrastructure. In many cases, you push a firmware update.