Exactly, age matters. If a 20 year old is tearing up AAA, every evaluator is going to be more impressed than if a 26 year old is doing it. Wander Franco isn't the best prospect in baseball because he's hitting .341/.410/.560 between A and A+. He's the best prospect in baseball because he's hitting that well (in addition to being an average at worst defender at the most premium defensive position) as an 18 year old.