He's no rookie, that is clear.
OTOH, respected football people claim it takes from a minimum of 30 (IE: Pat Kirwan) to beyond 48 games started (IE: Jim Miller) to know who/what a particular QB is about/ceiling. Average from people around the league was about 45 starts-
"Has the player had enough opportunity—with proper scheme, coaching, and personnel—to show whether he is a QB you can consistently compete with? The exact time frame needed to answer this question differed among the folks I spoke with, but the ballpark seemed to be around 45 starts, or about three seasons’ worth."
This from a Ringer article by Robert Mays
JB isn't near the end of the 'QB eval period', no matter how many years he's been in the league.