So the way I see it, there's a couple possibilities

1. Rodgers stays healthy this year, ZW plays limited to no snaps. In this case, no way the 5th year option gets exercised.
2. Rodgers gets hurt and Zach plays meaningful snaps
   1. Zach plays poorly or just OK, doesn't get his option exercised
   2. Zach plays lake a franchise QB for an extended period of time, gets his 5th year option exercised.

Unless 2-2 happens, then Zach again goes into 2024 as the backup (and without franchise invested in him anymore), either behind Rodgers (if he returns for a second year) or behind some other vet.  Barring injury, he again doesn't have the chance to make a big splash, so hits the market with limited interest and teams considering him as a backup only 

Bottom line, at some point he has to step in for an injured starter and play very well - could be this year, could be next year, could be after that on a different team