I hate unnuanced points likes these.
Many different reasons why 2nd year qbs get back to earth.
For the Browns its scheme and Baker trying to make plays on the run that he doesn't have the arm talent like Murray to make.
As long as K2 and K1 continue to evolve. Murrays arm talent release included will make up for a lot as well.
It's not even that IMo it's simply Cleveland's OL is terrible but they spent money going to get Wr's to throw the ball to. So the OC/Coach has a dilemma they're clearly better running than throwing because of the OL but he's got 2 really good Wr's so he feels compelled to throw. Instead of tailoring the offense to fit what they can do OL wise, he's asking the OL to block longer than they can on deeper routes. They showed it duruing the 49ers loss I can't remember it exactly but Cleveland is running a much deeper pass route offense than most teams in the NFL, the exact opposite of what they should do with that OL.
IN general I think QB's who peter out in year 2 etc due so for reasons like injury, or because they were put in systems schemed for them but over time became tough to sustain. both RG3 and Kaep fall into the latter, they were great but anybody who knew anything about physics and sports medicine could see they were taking too many big hits and it if it continued, they'd get hurt. the coaches inevitably tried to get them to play in the pocket more and they fell apart.
Kyler is already a pocket passer, we run him yes but we really aren't rolling him out much. Look at the offense Shanahan did in Denver for Jake, and how once they tried to make it less rollout centric, Jake couldn't do it to his satisfaction so he drafted another QB. Look at what the same coach did with RG3.
Yes we have tailored the offense to Kyler but it's not a bunch of misdirection rollouts, or things like that. We actually drop back and throw the ball from the pocket quite often.
Yes teams will scout him and get tendencies etc but I don't think his success is anything like some of those other guys and unlike RG3 and CK, Kyler doesn't get hit much. I don't care if he sits down or not if he is not getting hit I'm fine with it.