Originally posted by NinerBuff:
From the beginning of last season, I was on the "play Trey from day 1" train. But what Purdy is doing is demonstrably better than any Niners QB has done during the Shanahan era.
Any offseason talk is irrelevant, other than the fact that Purdy shows that Jimmy is redundant and expensive. It also seems unlikely for the FO to pursue another QB in FA.
Our QB's going into 2023 season will be Purdy and Lance. Unless Purdy wins a SB and/or continues on this pace to the SB but loses while putting up a huge game (like Josh Allen last year), it'll be a competition.
We'll have two very promising young QBs and the money to play Bosa, etc.
And people are complaining?? 
To me the biggest advantages that Brock has over Lance are:
1. Experience. Brock started all throughout high school and started all throughout college. He has thousands more QB reps and it shows. The footwork is a lot more clean, he appears to be more decisive and hangs in there when things fall apart around him because unlike Lance playing at NDSU which is the Alabama+Georgia of the FCS, Purdy always played on teams that were typically lesser talented than their opposition. He was regularly expected to pull plays out of his butt for his his teams to be able to compete. Lance had to come in and just run the system and let the talent win out, he was doing more of what Purdy is expected to do now with the 49ers when he was playing for NDSU.
2. The release. Purdy has a much more compact throwing motion and the ability to throw from a wide variety of angles that you just haven't seen from Trey. He's got a much more laborious delivery that does somewhat telegraph to defenders where the ball is going. Its something that you can definitely work with, see Philip Rivers who had one of the ugliest throwing motions that I've ever seen, but he made it work for him and was a top QB for many years. The Chargers even moved on from Drew Brees in favor of him. Brock is closer to Jimmy with the ability to get rid of it quickly, even in tight spaces.
3. Agility. Lance is more north-south fast but not really agile. Purdy isn't really fast but he's got agility that allows him to elude defenders in the backfield to a degree that I we haven't seen from a 49ers QB since Jeff Garcia. I think with experience, Lance can develop his pocket presence and movement more but he doesn't appear to have the same quick feet or lateral movement that Purdy does.