Expert testimony just mean two opposing claims paid for by the respective sides. The jury is in no position to determine which claim is more correct.
Do you have any evidence or studies to suggest juries can’t determine credibility of expert testimony?
In theory, that is the purpose of the lawyer(s) -- to try to ground the technical expertise in a way that the jury (and often the judge!) can understand and assign value/import/trustworthiness/credibility to the testimony and exhibits they are given.
in theory.
Society determines what is correct or wrong. A jury is a random selection of society. Anyone who wants provide a good to a society must follow principles set by the society.