> You don’t need social networks to keep in touch with anyone anymore, their original raison d'être is gone.

In what sense? The underlying social motivation/interest is still present. And it's not like fundamental communications capabilities have actually changed. Chat's been around since the 90s and SMS is the new email. And social network applications grew and thrived in those situations because pull-and-scan-social-feed across multiple circles has some distinct effort-reward profiles.

I could see the argument that the algorithmic and advertising imposition eventually drive out enough of the value that people opt out, but that's a statement about the business lifecycle of a social network app, not the underlying reason people might use / like them.