I did a Show HN a little while ago but you might want to check out TogetherLetters [0]. We made it to keep going with regular updates for groups of people (friends, family, coworkers, etc.) via email. Never shared on the web and it's consistent (bi-weekly, monthly, and quarterly in the free plan, weekly added in the paid plan). It might help solve some of your FOMO pain.
Unfortunately, in my situation, my family is so deeply steeped in Facebook that I have no choice. We already have group chats and the like, and some stuff gets posted there, especially if someone wants me in particular to know something. But if you try to go down that road, you're only going to get the newsworthy headlines: your grandma died, Matt had a kid, etc.
But in a lot of cases, people just want to shout little things at the world, and when my family does that, it's on Facebook. It's unreasonable to expect everyone I care about to announce everything twice, once to everyone and a second time to just me, so I knew I was going to miss some things. But recently it came to my attention just how much I was missing, and it's just not worth it. You only get your family once. Keeping up with the little things means getting back on Facebook, so I'm back on Facebook.
Thanks. And I feel ya. I have the same hate/love relationship with WhatsApp (another FB property - can't get away from them) with family there posting good stuff sometimes but some individuals blindly forwarding and reposting garbage where a good 50% or more is easily disproved with one web search. Frustrating.
[0] https://www.togetherletters.com