There's more to being the starter than your passing ability. I love Jake's pluck and grit, but his accuracy on most longer throws is not great. It is a place he needs to improve. Jake's experience, size, knowledge, team relationships maybe, etc are why he is the starter. Not his ability to hit 'em in the hands in stride on a 20+ yard route.
Cooper is a more accurate passer over 20 yards. He is also exponentially faster on his feet.
That's all i was saying. Not really a dis to Jake. Just one guy vs. another.