[AnthonyMouse]

The way free speech works isn't that nobody is ever wrong, it's that the debate ultimately leads to the truth.

People who don't understand science don't trust random scientists, and there is a reason for that -- anyone can put on a lab coat and say whatever they want. You have to consider the source and actually read the research and determine if it's credible. Most people don't have the training for that, and many of the others don't have the time, but that's not a problem as long as you trust someone who does. Your brother in law is a chemist and you trust his opinion; he trusts the CDC's. When your trusted chemist and your trusted nurse disagree, they get together and hash it out and if they're both being reasonable then one ultimately convinces the other.

The problem comes when you introduce a culture of attacking rather than debating people. Because you're not going to silence the CDC, but you may very well silence the brother in law, and then you create a group of people who don't trust anyone providing the true facts because everyone within their in-group is being silenced.

Which is why, despite a century of various fringe anti-vax misinformation, it's only now, in the climate of filter bubbles and deplatforming, that enough people believe it to compromise herd immunity and allow diseases like measles to stage a comeback.