Social Media is not the purest form of democracy because the people using social media, or who have a lot of followers on social media, are not representative
Mob justice is the purest form of democracy (how do the people organize in a land with no laws? They get pitchforks to oust the Bad People)
Social media is a tool that happens to facilitate mob justice particularly effectively. Why? Because you used to have to gather dozens or hundreds of people in the town common before you could yell “Burn the witch!”. Now you just tweet it (or share it, or telegram it, or…)