Chazal were misaken that during yom tov an am haaretz has the status of a talmid chacham regarding being trustworthy about certain areas of tumah and tahara (kol yisroel chaveirim baregel) in order to allow people to eat with each other and create achdus in Yerushalayim. (Ir shevubrah loh yachdav)
I don’t want to bash minhagim but this should be mentioned.