Mastadon is why we try to insulate platforms like Twitter from liability for their users' content: by not crippling them with it, we allow other, potentially better platforms to rise up in their place. That can't happen when we force platforms to behave in certain ways. Such regulation forecloses new player entrances and end up favoring the existing, imperfect businesses. (Hi fellow Mastodoners, this the the kind of thing I talk about...)