I did the same for a friend's birthday recently: put together a bunch of mix CDs as a present. My concession to the fact he probably doesn't use a CD player much was a QR code, with a link to a matching Spotify playlist.
Two years ago, we sent CDs as our wedding invitations. We also received a lot of feedback to the effect that lots of our guests had difficulty finding a way to play the discs (including at least one person who was incredulous that the CD was real; but that might be because we sent vinyl-effect CDs).
I put a Spotify code[0] to the playlist on the back cover as a concession to streaming, but if anyone knew what it was and used it, they never told me.
I put a Spotify code[0] to the playlist on the back cover as a concession to streaming, but if anyone knew what it was and used it, they never told me.
[0]: https://www.spotifycodes.com/