Obviously Facebook took off once it dropped the ‘college student’ requirement and opened up to the general population. But once that first generation aged up, the younger generation didn’t follow and Facebook became the place your grandma posts Biden conspiracy theories. Widening your target audience can get you an initial boost of users, but you end up competing with every other platform doing the same thing. Then some new platform opens up, all the cool kids go there, and the old platforms gradually get dumber, withers away, and dies.