According to NFL.com Wilson has been named the starter week 1
I feel like Wilson getting named had more to do with how bad Fields looked than how good (or not) Wilson did.
It seemed like they wanted him to show he could actually challenge for the spot, and he utterly failed.
It's Russ. People hate to hear it but his advanced stats were actually pretty good last year. He was near best in the league in the red zone, passer rating was good, TD/INT ration was super good he just couldn't run the offense Payton likes to run. Tomlin's historically ran an offense that fits Russ much better. Big Ben played a lot like Russ in many ways. I think Russ has another solid year and people go crazy because of it.
Russ's Advanced stats were not actually pretty good last year. His basic stats were pretty decent, but not his advanced ones.
He only had one, passer rating, that was above league average (and Passer Rating is the simplest advanced metric for passers since it mostly just measures basic stats and applies a multiplier to come up with a number). Every other 'advanced' metric, like Success Rate, ANY/A, EPA, QBR he was a bottom half QB.
He didn't just not 'run' the offense the way Payton wanted; he didn't run it effectively. Russ was a below average QB commanding a below average offense. (18th or worse in scoring percentage, yards per drive, play per drive, and points per drive).
And this isn't just numbers. You can see in the film what Russ's problems were.
He held the ball too long leading to lots of pressures and sacks because he refused to throw into tight windows and relied heavily on 'safe' checkdowns which padded his completion percentage and lowered his INT % but failed to move the offense. Russ threw passes behind the line of scrimmage at the 2nd highest rate of any QB in the league, throwing the ball BEHIND the LOS on more 1 out of every 4 pass attempts.