Mine are teens now. Late ex-FIL always got them a picture nativity calendar to share and when they were little we had to really monitor whose turn it was because they both wanted to open the door and see what was behind it.
I have a reusable one and they're still as interested in the activities I put in on some days (watch a Christmas film, bake something Christmassy) as they are in the chocolate. Appreciate that's still "more" than picture calendars.
We also have a Die Hard calendar where Hans Gruber is falling off Nakatomi Plaza, and you move him closer to the ground each day. They like that, too.
I've seen some beautiful picture calendars that are probably aimed at adults and I think my teens would also enjoy opening the doors on one of those.
They also both still enthusiastically help decorate the tree every year.
It's about the countdown to Christmas and feeling festive. I think my two genuinely enjoy giving as well. Not going to claim they like giving as much as receiving. I'm not that naive 😂 but they get into the spirit of things.
I do think that if these things are part of your family tradition then you never really grow out of them.