'Our sister died of cancer because of our mum's conspiracy theories'

The daughter of a former NHS nurse, struck off for promoting misinformation about Covid, has died of cancer after refusing, apparently under the influence of her mother, conventional treatment that medics said would have given her an 80% chance of recovery. The mother is now accusing the NHS of murder. She's apparently some kind of online influencer, peddling medical misinformation and bogus treatments (e.g. apricot kernels) in exchange for money. Anti-medical beliefs about cancer are said to be on the rise.

Why do people fall for this rubbish? Not the daughter, as any child or, in this case, young adult diagnosed with cancer and with a con artist harridan for a mother is clearly highly vulnerable. But anyone else, particularly older people and anyone not in a dire medical situation. Do they not realise that instead of being the incisive questioners of conventional wisdom they seem to think they are, they're behaving as if they're dumber and more gullible than a bag of hair?