I'm not going strictly on yardage totals - I've said several times I thought he played well other than those plays - admitting he wasn't playing at an elite level. If you look at the history of the discussion, I'm not claiming Dak played at a star level, just that he played well rather than horribly almost the entire game as the OP indicated,
In any case, while I get that a QB shouldn't get too much credit for an easy throw, it's certainly not fair to judge as if certain passes didn't happen either, or to suggest that if you remove those yardage totals his yardage was insignificant. Suppose Cooper had been tackled immediately after the catch in both cases. How does it make sense to judge as if the drive ended without that throw and catch having ever happened, not considering there was a throw and catch and yardage gained at the point of the catch that was sufficient for a first down, and therefore the drive would have continued even without the long runs after the catch. Who knows what Dak may have done, good or bad, after that, but it makes no sense to judge him as if there weren't ongoing drives prior to those passes.
And, neither was a 5 yard pass. I believe someone wrote the 90 yarder travelled 27 yards in the air, and as we saw, it was dropped to the receiver with 3 defenders around Cooper. Pretty damn nice throw really. The 40 yarder was, admittedly, an easy throw, although still I think 10-12 yards in the air, but we don't judge other QBs by ignoring their easy throws, so why should we do that with Dak? Besides, part of making easy throws is making proper reads, and a QB does get credit for that.