Oh no no, absolutely not. I only keep a handful of cassette tapes around for nostalgic reasons, and I don't have a tape deck anymore, because it seems rather pointless, as you say.

I just like to hang on to obsolete media that once meant the world to me, so I have a couple of tapes, some 3.5" floppy disks and a couple of MiniDiscs (still shrinkwrapped), purely for nostalgia and maybe one day as something to show the eventual grandkids.