Other than a couple of recommendations for Friendica, it looks like everyone hasn't bothered to find a replacement that does all the same things.

Friending all your relatives on Facebook was like attending a family reunion that never ends. At first, it was great catching up with everyone you hadn't been in contact with. Pretty soon after that, Uncle Bert would start on some political rant, Cousin Stan would try to get you to invest in some sketchy startup, and Cousin Sally would go on about a new cult she joined. The same thing would hold for an endless high reunion.

Facebook made sense for its original membership of college students. It was a great way to meet other students. You all had similar goals, experiences, and questions. Once you graduated, you all went your own way.

Social media is in its infancy in regards to how we use it. We're still learning about what works and what doesn't. For many of us, Facebook doesn't, more selective, less overall encompassing communication does. It's probably why we're all here on Lemmy and Mastodon.