Everyone reacting about the offense...

[Laloosh]

It doesn't matter much if RW is 10/35, 100 yards as long as those 10 completions are on 3rd downs.

Kaeps or 49ers numbers might not be impressive as a whole, but he gets the job done on 3rd downs leading to long sustainable, time eating drives.

That usually end in a field goal...

3rd down conversions:
RW: 57 passing, 6 rushing for a total of 63
CK: 53 passing, 11 rushing for a total of 64

Average drive by team:
SEA: 29.7yds, 2.12 points, 2:41 starting (on average) from their own 31 scoring 40% of the time.
SF: 27.5yds, 1.96 points, 2:36 starting (on average) from their own 31.9 scoring 37% of the time.

Russell also has a higher TD percentage but that isn't quite as relevant with regard to your statement about 3rd downs.