But he would have gotten better coaching ofc. So Jimmy would have started in 21' (Zach's rookie year) just like he did. He got injured later in the year if I recall and we saw Lance come in and immediately get injured. They wanted Lance to take over in 22' but it became so clear that he wasn't ready that Jimmy after being cut, was resigned by the 49'ers and they had drafted Purdy that year as well. As it turned out after Jimmy G and Lance both got hurt Purdy came in and played great.

Zach would have gotten a chance in the 21' season and been handed the reigns in 22'. He likely would have done better than he did with the Jets just through getting better coaching. But we'll never know how it would have ended up.