150 years ago if you shected a animal and had a shala about the lungs almost any Rav could answer it. Most could answer Kashrut questions as well
Today most cannot answer Shaalas about Kashruth (I am not talking about the kind if you accidently mixed meat and milk or other common mishaps that could happen in your house, but more from the food making end before it reaches your table) People who are throwing darts have no idea what goes on before the food even reaches the store and most Rabbanim dont either, Many are even industrial secrets. The OU is one of the few places that are experts in this field. They are one of the few that has access to the industrial factories and really knows what going on.