Honest question, do you really think that if Facebook disappeared tomorrow anything would change? Considering the complaints about Facebook plague every other social website including Twitter, Reddit, and YouTube. That's also assuming another social media site won't rise up to fill that same role (maybe an existing one)?
Would one tobacco company disappearing reduce cancer rates? No, but it's a start.
Every social media company that optimizes for "engagement" (which means addictiveness and the promotion of polarizing and triggering content) is part of the problem but Facebook is probably the largest player here.
These companies are making billions off the collective lobotomization of humanity.