Why carrying it is practical? What is it used for?
The only time I need my ID is during elections, but I can also show the one I have in our government produced app.
Older people in Poland do carry those, mostly out of some kind of habit and some kind of fear that police might need it. I can drive a car and get a speeding ticket, and all I need police to know is my ID number (it is not the identifier of my identity card), which I know by hard, it consists of my birth date plus 5 semi-random numbers). I don't need my ID, my driving license nor my insurance data - everything is located in police database based on my ID number (or my license plate).
Bad sides of carrying it is that you might loose it, and that is a PITA, because you need to block it right away (someone might take a loan with it, happens I kid you not) by calling your bank or similar service.
So I take it out from my wallet (which I don't carry also) only when I go to the airport.
Carrying it is practical and most Germans do carry their ID, but it's not a requirement.