Notable blurb from the report itself --- "However, whilst this approach [content removal] may be effective and essential for illegal content (eg hate speech, terrorist content, child sexual abuse material) there is little evidence to support the effectiveness of this approach for scientific misinformation, and approaches to addressing the amplification of misinformation may be more effective. In addition, demonstrati…
I agree that the link between online misinformation and real world harms is tough to measure. I've read some studies of radicalization that found meatspace was the primary avenue for radicalizing, even if cyperspace allowed extremist groups to raise more awareness, and I suspect the same is currently true here.
However, I don't think this is some "constant of human nature" and is more likely an accident of our current society. As people grow up with and on the internet, I would expect this to change: I would expect the link between online communication and radicalization to strengthen over time.