"The business choices of internet platforms have enabled an explosion not only of white supremacy but also of Covid denial and antivax extremism, which have variously undermined the nation’s pandemic response, nearly sabotaged the presidential election, and played a foundational role in the violence at the Capitol. A huge industry has evolved on the platform giants to raise money from and sell products to people in the thrall of extreme ideologies."
Also, their monopoly power means no meaningful alternatives can exist for businesses who want to advertise or people who want to socialize on platforms that act ethically.
Wired