Systems that only work to converse with your "friends" (which I put in quotes, as we use that term so liberally online; just like, an opt-in follow mechanism where you can't be spammed by random strangers) are still "social".
It only dies if it's out-competed by something else. When you make a change to the law that everybody has to follow, you can end up just turning everything to shit because nobody is allowed to do better.
Near a small town there was a small lake. Many people loved to swim in the lake. One year, a terrible accident resulted in harmful pollution spilling into the lake. No one swims in the lake anymore.
They haven't stopped swimming because of some better alternative. They stopped swimming because swimming conditions have changed and now it is a bad idea.
If section 230 is repealed and social media becomes too toxic for most people to use, of course people would not stop communicating. The vast majority of human communication doesn't even occur on social media.