Except that FB is actually tragically awful at these things because the way the algorithm is a black box that always changes, you don't have anything reliable about who sees what… and to really promote something so people see it, you PAY for it to be boosted, so it's no better in that sense than the old newspaper analogy!
Let me tell you a personal story: My sister is one of those people who just throws stuff up on FB like anyone else. People not on FB miss it. A couple years ago, someone inspired her to send a personal email to close family just sharing updates about what's happening with her and inviting others to reply the same way. It immediately felt more personal and meaningful and brought out different context and closer relationships compared to anything that happens on Facebook. It died away after a little bit because we failed to keep up a routine… but I predict that if your cousin sent you vacation pictures not in a just "email everyone" sense but in actually thinking of YOU, it would actually feel good and bring you together in a more meaningful way… but I don't know you or your cousin, of course.
Let me tell you a personal story: My sister is one of those people who just throws stuff up on FB like anyone else. People not on FB miss it. A couple years ago, someone inspired her to send a personal email to close family just sharing updates about what's happening with her and inviting others to reply the same way. It immediately felt more personal and meaningful and brought out different context and closer relationships compared to anything that happens on Facebook. It died away after a little bit because we failed to keep up a routine… but I predict that if your cousin sent you vacation pictures not in a just "email everyone" sense but in actually thinking of YOU, it would actually feel good and bring you together in a more meaningful way… but I don't know you or your cousin, of course.