Twitter is popular with journalists, politicians and such. Hence all the attention. For most people, facebook and youtube are the important part.
IMO, youtube is the most important medium today. It's effectively the free-to-air TV of the internet. It has a terrible, clunky, disrespectful and illiberal approach to content moderation. In fact, it's pretty similar to state censorship methods... ambiguous rules, selective enforcement, whipping boys. Makes Twitter look good.