I voted for Angel Reese for Defensive Player of the Year. DPOY, along with the All-D first and second teams, was one of the most humbling parts of the voting process, and I spent a lot of time going back and forth.
I might be projecting, but I think understanding defense on an objective, individual basis is one of the hardest tasks for an outside observer. At a base level, it's sometimes hard to know what a player was being coached to do. On a personal level, I don't have enough of a thorough schooling in the ins-and-outs of defense to understand it intimately.
So, here's what I did: I went back and watched more than 150 defensive possessions each for Angel Reese, Gabby Williams and Shakira Austin. I tried to value a) how much they made life miserable for their opponents, b) how much defensive responsibility were they trusted with, c) versatility and d) individual contribution independent from team context.
I came away really impressed with Angel Reese's anticipation and athleticism, as well as her ability to hold her own on an island and cause problems in drop coverage. She does a lot; the clip I shared a couple of weeks ago has some examples. The motor is always there. I think you can split hairs and raise question about her rim protection, but I really came away from the film believing that she was the best defender this year. I'd like to know more about the game than I do now, so that belief may or may not be correct.
As for the others: I don't think there was a "wrong" choice for DPOY among the contenders. Gabby Williams wreaks havoc and is crucial for Golden State's defense. Her stats would look gaudier if she played more, and her perimeter defense is top tier. (Though, when I watched, I kept coming away thinking about Kiah Stokes's rim protection.) Don't think many players want to deal with A'ja or Shakira Austin at the rim, either.