The big picture matters because you're the one making definitive statements on the outcome of Fields career. You're the one who said he'd never win a super bowl. Maybe you're right, a lot of players don't win a super bowl. But then again, maybe he will. He's in year 2.
You're also comparing him to QBs with significantly better supporting casts but expecting Fields to produce like Mahomes, or Tua, or Burrow, etc. Situations and supporting casts matter in football. His supporting cast is not good. You have to take that into account when evaluating any QB's situation. Zach Wilson got a shit ton of help last offseason and he still looks awful. That doesn't bode well for him. Trey Lance, if he were healthy, would have arguably the BEST supporting cast in football. If Fields were in SF, they're super bowl favorites. Trevor Lawrence also got a ton of help in the offseason, he hasn't looked good yet either but still early. Mac Jones had a good rookie season and has fallen apart this season so who knows what to make of him. Just because those QBs have struggled, it doesn't mean I'm going to immediately and declaratively state they won't ever win a super bowl or that they can't get better. That's a completely unserious take.
Fields has had several bad games to start the season and has progressively gotten better almost every week. Last week wasn't a good game but he still put up 225 yds of offense and 2 TDs. The front office intentionally gutted the roster to rebuild. I don't care how great a QB is, they're not winning anything with this level of a supporting cast. Expecting him to be a finished product midway through year 2 is stupid especially with the growth over the season.
And if you've read any of my posts, I stick up for plenty of players. As I've stated before, I thought Kmet was just a dude but has really developed into a good player over the course of this season that I now believe can develop into an above average to pro bowl caliber TE. I was wrong about him. I believe Jenkins is a keeper on the OL. I'm not a fan of the current WR room but their struggles also tie into the fact the QB doesn't have pass protection worth a shit. Brisker has looked good. Eddie Jackson (who I was very critical of last year), seems to have bought in and resurrected his career.