Dak's playing the same level of football he has since about 2019 or '20. He's a sum-of-the-parts QB, and the parts around him right now are a broken OL, some sub-NFL RBs, two borderline NFL WRs, and a swiss-cheese defense.
Dude is the same guy from last season, he's just on a worse team and didn't luck into facing the 32nd ranked slate of pass defenses.
I would say that Dak's not a bad player, so much as he's a player with a ceiling. I would love to see him and Jared Goff switch teams, because IMO, they are very similar talents.
What's Dak worth on the open market... it's tough to say, cause the QB market is so broken. And IMO, it's due for a reset. How many Jameis Winstons and Joe Flaccos and Baker Mayfields have we seen just jump in and provide at least an adequate level of QB play for pennies on the dollar.
There's a two-tier QB market right now. Any starting QB gets a top-of-the-market, $50+ deal, even for guys whose teams have some serious misgivings (Daniel Jones, Murray, Tua, etc). And backups get like $5M max. I would like to see a $20M-$30M QB middle class emerge, for "trailer" QBs who can play well but aren't going to carry your team. Dak would slot in around there.
But that market doesn't really exist yet, and it won't until some NFL owners start saying "no" to their starter when he's up for a new deal.