I feel pretty justified describing Facebook in its current form as toxic. It may be accidental to some degree but Facebook as it is exists today preys on people's weaknesses and insecurities, privileges fake and alarming content, encourages habituated, addictive usage, and undermines normal face-to-face human interaction.

I think it's possible to design social media platforms without those qualities so I feel it's fair to call Facebook, like junk food or cigarettes, toxic.