You're wrong. You are just using an atypical anecdote. Normally teams pass when down big and defenses will play shell coverages to let them get underneath. That tends to inflate passing numbers and cut back on running stats.
https://www.espn.com/nfl/matchup/_/gameId/401437644
A more typical game from that early period was the TB game. Not great YPC but TB just keep sustaining drives with runs, particularly in the first half. That kind of stuff kept rearing its head all season up to the playoff loss (10 play 91 yard drive by SF including 7 runs to seal it):
1st & 10 at SF 9
(5:58 - 3rd) PENALTY on DAL-D.Lawrence, Neutral Zone Infraction, 5 yards, enforced at SF 9 - No Play.
1st & 5 at SF 14
(5:58 - 3rd) (Shotgun) C.McCaffrey left tackle to SF 21 for 7 yards (D.Wilson, D.Bland).
1st & 10 at SF 21
(5:19 - 3rd) B.Purdy pass deep middle to G.Kittle to DAL 49 for 30 yards (T.Diggs). 4 YAC
1st & 10 at DAL 49
(4:28 - 3rd) B.Purdy pass short middle to C.McCaffrey to DAL 41 for 8 yards (D.Bland; A.Barr). 3 YAC
2nd & 2 at DAL 41
(3:47 - 3rd) (Shotgun) C.McCaffrey left guard to DAL 36 for 5 yards (A.Barr).
1st & 10 at DAL 36
(3:08 - 3rd) C.McCaffrey right tackle to DAL 28 for 8 yards (L.Vander Esch).
2nd & 2 at DAL 28
(2:28 - 3rd) (Shotgun) E.Mitchell up the middle to DAL 22 for 6 yards (D.Bland, L.Vander Esch).
1st & 10 at DAL 22
(1:44 - 3rd) (Shotgun) E.Mitchell left guard to DAL 20 for 2 yards (D.Armstrong).
2nd & 8 at DAL 20
(1:06 - 3rd) (Shotgun) B.Purdy pass incomplete short middle to B.Aiyuk (A.Barr).
3rd & 8 at DAL 20
(1:03 - 3rd) (Shotgun) B.Purdy sacked at DAL 26 for -6 yards (sack split by D.Lawrence and L.Vander Esch). PENALTY on DAL-D.Wilson, Defensive Holding, 5 yards, enforced at DAL 20 - No Play.
1st & 10 at DAL 15
(0:37 - 3rd) (Shotgun) D.Samuel right tackle to DAL 15 for no gain (D.Lawrence; A.Barr). PENALTY on DAL-J.Hankins, Defensive Holding, 5 yards, enforced at DAL 15 - No Play.
1st & Goal at DAL 10
(0:07 - 3rd) K.Juszczyk left guard to DAL 2 for 8 yards (M.Hooker; L.Vander Esch).
2nd & Goal at DAL 2
(14:58 - 4th) Christian McCaffrey 2 Yd Rush R.Gould extra point is GOOD, Center-T.Pepper, Holder-M.Wishnowsky.