I wrote a book ab this. It isn't evenly distributed. It happened gradually over a decade. Recommendation engines helped. But mostly it's the product of a propaganda campaign that made being anti-vax an article of *right wing identity*.
📖 Invisible Rulers: The People Who Turn Lies Into Reality.
RE: 
Bluesky Social
Aaron Rupar (@atrupar.com)
Support for vaccinating kids against infectious diseases dropped from 81% in 1991 to 51% last year
We are getting dumber as a society