Folklore: 1. the traditional beliefs, legends, sayings, customs, etc. of a people. 2. the study of these

"...why should people accept that their new version is any more accurate?"
Why should people accept any new ideas?
People should investigate available evidence proving or disproving the idea, or take into consideration a lack of evidence.
Evaluate same and decide if you have enough to make a conclusion. Make your conclusions based on your own personal judgement if you feel you can.
Re-evaluate conclusions when new evidence or insight becomes available.

There are people who believe the earth is flat or that the guy living next door to them is a vampire. On a personal level, it doesn't matter. (Well, not unless they they start sharpening stakes.) On a public, scientific level, it takes a bunch of respected smart people whose conclusions, as a group, are perhaps more reliable than any one individual's. And it STILL comes down to them being more likely to be correct, not guaranteed to be correct.

I believe most of the changes in scientific conclusions over the years have come about because of new evidence and not because people have made errors in evaluating previously available evidence.