While you're not wrong that a crystal radio does work without power, you do actually need to have a crystal radio in order to use one.
There are probably more homes with a charged USB power bank that could power an FM or DAB radio than homes with a crystal radio or the means to build one.
Yes, it is not generally available but as an anecdote I mentioned crystal radios because I don't know that from my technical school or university degrees but thanks to my grandfather who didn't go to an university.
There are probably more homes with a charged USB power bank that could power an FM or DAB radio than homes with a crystal radio or the means to build one.