I'll just say this regarding Carr. I think Carr is a solid QB, but I think his Wins/Losses are very deceiving this year compared with Rattler.
Derek Carr's record against teams over .500 this year is:
0-3 (Chiefs, Eagles, Rams)
Spencer Rattler's record against teams over .500 this year is:
0-4 (Bucs, Broncos, Chargers, Packers)
Derek Carr got us wins against the Giants (our defense held them to 11 points we scored 14 points), we easily beat the Browns, and we squeaked out a win against the Falcons holding them to 17 points (and lost to them once). These listed games all occurred while our team was decimated with injuries and are comparable to games Rattler has played in with lackluster supporting cast. During this run of games we also lost to the Panthers once with Carr starting at QB.
It's hard to even include the first 2 games of the season vs the Panthers and Cowboys given how much different our team looked in those games with the players that were healthy and available.
I do think Carr is still "the best QB" on the roster currently, but I'm not sure that will be the case long term. Rattler has shown some real nice glimpses of his potential at times and has played some really good halves of football (1st half vs Bucs, 2nd half vs Commanders, and 1st half vs Raiders were all excellent), but hasn't put together a full game (yet). I just can't help but think if our defense was playing at a higher level like in past years or if we had reliable weapons on offense, that the narrative on Rattler wouldn't be more positive right now from many in the fan base. I'm excited to see if he can continue to develop going into next season.