The reason is simple: most of us, even those of us who are scientists ourselves, lack the relevant scientific expertise needed to adequately evaluate that research on our own. In our own fields, we are aware of the full suite of data, of how those puzzle pieces fit together, and what the frontiers of our knowledge is…
There’s an old saying that I’ve grown quite fond of recently: you can’t reason someone out of a position they didn’t reason themselves into. When most of us “research” an issue, what we are actually doing is:
formulating an initial opinion the first time we hear about something,
evaluating everything we encounter after that through that lens of our gut instinct,
finding reasons to think positively about the portions of the narrative that support or justify our initial opinion,
and finding reasons to discount or otherwise dismiss the portions that detract from it.