The defense looked fine, except for a few crucial missed tackles and awful penalties. They clearly went into this game to take away the big play and make Dak earn everything. It worked for the most part. Sure, they gave up yards, but that will happen when you play this style against good offenses. Ultimately, the game plan gave them the opportunity to win the game, and they came up short.
The only major issue I saw is one we've known: without Nwosu, the Seahawks' defense can't create consistent pressure. Without that disruption, they're asking a lot out of secondary, particularly the safeties, in coverage. If I were to point blame, that's where I'd look. For the past five years, most analytics have shown that you need an elite defensive line to have an effective defense. And until recently, the Seahawks have built around their secondary. They don't have a top-20 player on the D-Line, and their best player is Williams—who they got during the season. That's what separates the Seahawks D from these other teams. Dallas, for example, had similar struggles as the Hawks, but their D-Line dominated when it mattered on those last three drives.