Rather then step in as arbiters of truth, they should provide tools, links and APIs to let their users decide what is true and what is misinformation. If their users express some concensus, like 90%+ of real human users, then I think they’re right to demote or provide warning labels on particular links.
It’s a matter of time. Just like with software, you have to have a bias toward open source, freedom respecting objects and support them with your cash.