There are mentorship and professional groups there that aren’t available elsewhere.
Plus, the local groups for my town/state provide crucial information about weather, taxes, traffic, river safety, etc. In general, it’s a good source of knowledge.
I hate that I’m giving up privacy, but there are also no other social media networks that can compete. I can’t message/Signal my closest 5,000 neighbors to find out which local/free berry patch is ready for picking. But, there’s a fb group for that.