I think you need to define what you mean by those two terms. Is a pro the average open player? 100 rated player? 1040 rated player? Is an average player the average tournament player? Average am? Average of all the people who play at least once a year?
Sure there's not an enormous gap between a pro and an advanced player, but comparing the top level pros with the average two discer I see on the course would be a difference of 2+ throws per hole, that's a pretty big gap.