CJ Stroud had a rookie, defensive head coach from the Niners and a rookie offensive coordinator who came from the Niners. That’s exactly what Zach had.
DeMeco is a better head coach than Saleh, and Houston would have been a better situation for sure. Where you end up can play a part in a player’s success. There’s obviously no way to know who would have been successful I situations they didn’t have. But good QBs overcome bad situations.