Any given area of medicine is by itself a hugely complicated subject, much more so than climate science. There is no hope of understanding all of it, even in say the treatment of a specific disease type. What you have to do is understand the current general consensus position, and then be able to use your experience and knowledge to colour which bits are more or less reliable, and then interpret new information in that light.
I have just come off a call discussing a possible new combination treatment we are working on for a type of cancer, and this needs me (clinical scientist) and the physician for compound A, with our translational scientist, preclinical scientist, the pharmacokinetics goons, the predictive scientists, and also some modeling nerds looking at toxicity. Then add the same group of people for the compound B in the combination. These are all experts in their areas, but there is just too much for any given individual to know. We have to rely on their knowledge to get started.
It is in fact completely wrong to say the only important thing in science is what you can prove. Nobody would get anything done. Go to any medical conference (maybe not this year) and there will be a host of "how I treat" sessions. You need to understand and trust the general information before having innovative ideas.
We* are smarter than you**. The lay person is well advised to go with the general scientific consensus, whether its climate science, wearing masks, or vaccination.
*meaning scientists en masse
** as an individual