The problems with social media are largely around removing all friction from the process, and adding a huge dose of virality and highly specific targeting. The former means people get a vast amount of information with minimal effort, and the latter enables targeted propaganda which then gets magnified in echo chamber bubbles by the algo.
The individual elements all existed before, but the combination creates pretty unique effects. I'm also skeptical these companies can effectively address the problem since these properties are what has fueled their growth.