If said authorities were infallible, I'd agree with you. Unfortunately that is rarely the case.

Nature is full of poisons too. Sugar is one! (In the right big and/or chronic dose. Organisms have to deal with glycation damage all the time.)

"Not infallible" doesn't mean "always wrong". Just because FDA made some mistakes, doesn't mean you can start doing the opposite of everything they say and live a happy and healthy life.

Authorities may be "in the pocket of Big Pharma", but by default, I'd still trust them much more than yours or mine non-expert opinion.

Authorities don’t have to be infallible to have a better track record than anyone else. If they did, we wouldn’t have senior software engineers, we would have the pointy head boss writing all the code; we wouldn’t have doctors, as everybody’s home remedy would be just as good; we wouldn’t have CEOs, as communism would be correct and the workers would be more effective at running their businesses than the owners ever were (hello ironic counterpoint); etc.

Of course, everybody including authorities is capable of making mistakes. It is generally a bigger mistake to think you know better than they do. Not always, but generally.