The defense that we played against Nebraska would probably cause us to most of the teams on the schedule; though I suppose Illinois is on the level of Duke so who knows, maybe we beat them anyways like in 2019.
I'd say Illinois is measurably worse than everybody else left on the schedule, and then you have teams like Minny/Purdue that are beatable, and then a step above that are teams like Wisconsin and Rutgers that are perhaps also beatable but just appear to be playing more sound football than we are.
Obviously, we hopefully never play defense like that again, but that remains to be seen.
I'm hopeful we see some changes because nobody wants to see that disaster again, but it's just hard to say what can/will actually change because it's not exactly clear what % of the problem is scheme vs execution.
I'm just not convinced we can execute defensively in a way that works if our players are continually not in position to make plays when and where they need to be.
Our players just don't look all that different (except maybe at LB) from what we've historically had under Fitz, especially the past couple of years when we had an elite defense every year.