My response to that tired theme: you don't need a mega $B valuation to pay for a simple social network for sharing baby pics with friends and family. A non-profit or a benefit corp structure would be just fine.
And people pay $10/mo for Netflix, why wouldn't they pay a few bucks a month for an actually good social network? Heck, make it free for a month or six, no credit card needed, and when people see how good it is they won't leave. I pay for Disney+ just to let my kids watch Disney movies BECAUSE THEY'RE GOOD.
People won't subscribe to a non-free Facebook competitor because Facebook is free and none of their friends are on the non-free competitor... And most of their friends never will be.
Most likely the product will be free for a while and switch to paid. It kind of sucks but for a really good product it could work.
This is almost Reddit's model (with Reddit Gold, and now the various other comment/post awards added recently), except Reddit also sells ads; it'd be interesting to see if the awards alone are enough to keep the lights on absent a need to appease investors.
Come on, can't anyone make a product that connects friends better than FB? I'm sure it's technically amazing, but from a product perspective, my god, look at the thing, it's an absolute garbage fire. You can tell from the notifications it sends that it wants you to watch shitty videos and read shitty news articles alone, not connect you with your friends.
Make a social network that feels like an actual social space and not an ad-infested media shithole, and I'll sign up, my friends will sign up, everyone will sign up, and FB will be toast in a couple months.