The list of QB's who have had multiple mediocre years but also great years is literally endless.
I could add 50 more QB's to this list.
What is the difference in the bad and great years? Supporting cast/Coach/System.
ALL of these QB's have proven they can throw accurate, read a defense and execute the system at a high level when the surrounding pieces are there. Any of these QB's could have had a Darnold year with the Vikings.
To assume these QB's suddenly remember how to throw a football and read a defense and then have years when they forget again is beyond absurd.
Blake Bortles
Alex Smith
Mark Brunell
Jake Delhomme
Sam Darnold
Baker Mayfield
Rich Gannon
Jim Plunkett
Eli Manning
Ron Jaworski
Doug Williams
Jeff Garcia
Trent Green
Goff
Patrick Mahomes:
2018 50 TD 12 Int 113 QB rating
2024 26 TD 11 int 93.5 QB rating
Clearly Mahomes forgot how to read a defense and throw a football.