Well, i have to say that is one area where Germany actually shines. We shut off the stupid, power-hungry and slow 3G, but kept 2G as a basic service. That was a very good decision. All data comms can switch to 4G/5G, while voice comm can remain on 2G as backup. Low data rate devices can also use 2G/GPRS/EC-GSM.
This is how it worked in the US until this year. 2G can actually work pretty well along side 4G and 5G, it never really needs to be shut down since it works in the guard bands of LTE (i.e. nothing else is using the airspace 2G occupies and never will).
