I think a lot of people, when looking at DT, only really look at the stat line for sacks. Sacks are great, but they're not the only metric. Darnold was pressured all game. Probably the biggest knock on him was that he was constantly fleeing the pocket, and it's true. If the QB is constantly fleeing the pocket, that means the DL are doing their jobs. It also means the defensive tackles, on the inside, are going to have fewer sacks.
Ed Oliver may not have looked elite yesterday, but he was by no means a weak link, or a liability. He played really well-- the entire line did. (That includes H. Phillips, IMO, although he didn't really see the field very much, IIRC.)