I see many people clamoring for the death of Facebook but don't they own many of the up-and-coming social networks anyway? If people are ditching Facebook for Instagram you might as well switch to cocaine to stop your crack addiction.
I've tried most of the big ones (except WeChat and other chinese apps, where I don't have a single peer), and I bet on Telegram. They're moving forward with incredible speed, and from all the competitors, they seem to understand their audience and usage patterns best.
Also, it's a platform that's already actively used for commerce. Just like with Bitcoin and darknet, drugs are the primary growth factor (I don't know of any other transactions cryptocurrency is actually used as currency). I expect that after they release their own currency, it will take over all existing crypto from sheer convenience.
Only reason I still have a FB account and not simply a messenger account is spotify is tied to it and I can't unlink from FB as the login source..
It might look different to most people, but given one still gets a "restricted" Facebook account created behind the scenes with a messenger account, I don't think people understand the privacy implications of that. See my other top-level post for my take on the issue.
WhatsApp on the other hand seems much harder to make money with.
In both cases though, I guess the good thing is that it's a step back from the all-encompassing and creepy global social network Zuckerberg had in mind for Facebook. Instagram and WhatsApp seem more moderate in scope in comparison.