I would put some blame on medical billing, and the opiods pandemic also made some fertile ground for trolls (a work injury turning family member to an addict, followed by minimal fines and zero jail time for the conspirators that grew the pandemic). Basically a perfect setup to grow mistrust.

Just a couple of decades ago both sides of the US political aisles laughed at antivax style rhetoric, and didn't see forcing the issue further than it was as worth it (us religious grounds and similar).