This is how I look at it. Let's set we had Graham, or Will Johnson, or Carter on this year's team. Would the Saints have won more games? Maybe. It would have at least been more interesting.
Now let's say that the Saints had Tet or Jeanty this year. Would the Saints have won more games? Almost certainly.
It's not just BPA. Its which player helps you win the most given what's there. I could be wrong, but I don't think anyone on defense does that, at least in the short-term, in the first round. After the first round is a different story.
Yes, the defense is old and needs upgrading everywhere. But it's not the total embarrassment that the offense is either.