Last year, as you say, we hit a brick wall way too often. That's when the impulse to abandon the run arises.
Now imagine that we had been getting 3 to 5 yards on those plays. Just that. No chunks.
Completely different situation. There would be no temptation to abandon the run. And the passing game would take off.
This is why I say that getting over the LOS consistently is a better measure of the run game than YPC, a stat often distorted by a couple of unrepresentative chunk plays. Can you get to 2nd and 6 or 7? That's the crucial test.
I feel pretty confident that McVay is focused on establishing a solid run game this year. To me, PS G1 showed a full squad that had put in serious work to be ready to get over the gain line. Love that, even if we never see these individuals. You know the starters have been working on this even more!