You only have 11 men on the field, sometimes your guy has to win your matchup. Neither of the two rushers was named Von Miller so it's not like they're going to draw a double team. Lamar turns that into a touchdown even if 1 guy loses there. None of the rushers went unblocked, so it wasn't a scheme problem, it was an execution problem.
You're missing the point. It's not that the play they ran couldn't have worked. It's that, yes, there absolutely was a better play that would've given the offense a better chance from 2 yards out.
Other teams run them pretty regularly. The Ravens have run them often in the first half of this season already. Teams literally dedicate practice time to perfecting these very plays.
If anyone here has ever played Madden, you'll recognize this play as Spot. A triangle read to the right with a corner, flat and spot route, the latter two being well covered.
They motioned the back out to a backside slant. From 2 yards out. No rollout or playaction fake or moving the pocket for Lamar. No real run threat on a straight drop.
If Roman already used all of his best short yardage plays from "the vault" earlier in the game, then they should've kicked the FG.