Purdy hands the ball off to CMC. He also gets to throw to CMC, Deebo, Aiyuk and Kittle. He has a better defense to keep his teams honest as well. And their special teams isn't as bad as ours. Oh and he's consistently had a well renowned offensive minded HC. People need to stop pretending in general that you can even begin to compare what Purdy looks like here vs his current situation.
Mac and Zappe would both be better there. They probably won't be anywhere near what Purdy is, but they would undoubtedly be FAR better in that situation than this one.