The best looking man in football simply isn’t a great QB, and a new age of football has dawned where more and more young quarterbacks are available every year that are straight-up good to great. While Jimmy G is good enough to give you a chance to win a ring, he’s got a pretty obvious ceiling, and Shanahan obviously greatly elevates his production in the Niners system. That’s fine and all to a point, but imagine having a guy who is uniquely talented outside of an offensive system suddenly pair up with Shanahan - the sky is the limit, as we’ve seen firsthand with Reid/Mahomes.
Lastly, the incredible value of having a guy on a rookie deal shouldn’t be understated, nor should having a top 5-10 quarterback who you’ll gladly sacrifice a Huge chunk of your cap space to retain. Instead, we’re stuck in no man's land with a middle-tier QB taking up a giant chunk of the cap space. It’s honestly one of the worst places to be in the NFL QB-wise: Jimmy is good enough that you can win with him, but not good enough to elevate the offense or the team around him.
Now for the super unpopular opinion: trade Jimmy and Warner (hopefully recoup a pair of 2nds) as well as Ford and Kwon (2nd and 3rd sound about right) and "tank" the 2020 season (probably still go 8-8 with CJ or Mullens leading this team tho, heck maybe even bring back Kap), sign Kittle to an extension, and trade the farm to move up into the top 5 to take Lawrence or Fields or Lance. It’s what’s best for the team in the long run and gives us a chance at an elite offense with a uniquely talented QB combined with Shanahan’s offense.