Why the low draft grades?

Compared to last year's draft, this year's draft was just as efficient and impactful if not more so. Let's look at 2021:
1-28: Payton Turner: We all knew this was a reach in the first round. He's shown some flashes, but hasn't been on the field enough to prove 1st round value. Plus, picking him after immediately signing Mr. Two-Firsts to a long-term contract keeps his playing time limited, regardless of health. Forced depth.
2-28: Pete Werner: Solid LB in 2021. Could be really good. Scouts did their job on this pick
3-12: Paulson Adebo: Looks like he could be great. Again, really good pick
4-28: Ian Book: Sigh. Moving on.
6-22: Landon Young: Started one game. Good depth maybe? Otherwise, nothing special.

So we got two great players in Werner and Adebo, and the jury's still out on Turner.

This year, we can fairly confidently say Olave and Penning will start from Day 1. Taylor looks to be a much-needed plug for the gaping hole left at safety, and will also most likely start. The others, like any late-round pick, who knows. So the point is, the Saints used their draft capital to get guys who should immediately be impact players at positions of need, with the usual try-em-out picks at the end.