Except in a winner-takes-all market. (This is not about making money, but still needs a critical mass of users to become successful because of the network effect).
Social media is only winner take all because the platforms are closed. If enough people say no thanks, that will change. The social networks might not need any one person, but they need all of us and a significant but small percentage can make a difference.
Why do we bother with signal if that's the case? Competition matters even when it seemingly doesn't because we raise the bar. Look how Viber and telegram stick out like sore thumbs (ignore the pos that is allo) because WhatsApp now has e2ee.