He wasn't used much for the same reason as the regular season - they need Zeke in for the blitz pickups and to pound the ball for first downs, because the o-line blocking is horrible.
Sad, Cowboys have had a great, great offensive line at least 3 times in the past - the 70's, the early 90's and the late 2010's. And you will notice that's when the playoff successes happened.
Still time to fix that, the defense has several young to very young good defenders, offensive linemen can contribute very quickly, Martin was All Pro his first year, Larry Allen by his 3rd year (and Pro Bowler his second), Tyron by his 4th (and he had to move from RT to LT in his second year), Frederick was a PB player by his second year.
The draft this year needs to be split between OL and DL, maybe a LB if a high ranked one happens to fall to Dallas' spot.
Otherwise we're just spinning our wheels, we'll see the same scenario we've seen for 26 years - one first round playoff win every 3 or 4 years....