Hmm. You need very occasionally, such as when opening a new bank account, to prove name and address - a utility or council tax bill, letter from the tax office, or even previous bank or a mortgage statement etc will generally suffice. There's a fair list of what is and isn't accepted, and it's fairly infrequently needed. Like only when creating a new and often financial relationship.
Can't remember the last time - ten years perhaps. Someone young setting up lots of things for the first time, much more often.
As for carrying them, yeah, that should not be necessary.