Was anyone calling him a bum in 2019 though? Jimmy G is a perfect example that most QBs in this league are going to be up and down. Also a good example that coaching, system, and surrounding talent has a ton to do with QB success, which is why I don't think you penalize Purdy for having good players around him, most "good" qbs do.
Right, you can catch lightning in a bottle every once in a while, it's consistency that's makes you the better quarterback...
you guys like Blake Bortles, Mr. butt fumble, and even Kaepernick and some others went to a Championship game or a SB... I mean if you really want to split hairs let's talk about the guy in the news Cam Newton he had one good year that's it one great truly transcendent year and didn't even finish it with the Super bowl win, outside of that he was inconsistent.. he never repeated it...
at least Prescott's been mostly consistent since the rookie of the year, he's played well since his rookie year, and he's had years where he played better but much like Mahomes is seeing this year last year coming off a broken hand and his receivers his offensive line and his offensive coordinator didn't do well enough to make Prescott look better his off year there was a real reason for it....