I'm in agreement with you on that one, and so is film historian Danny Peary. Check out his book Alternative Oscars in which he makes his choices for Oscar winners in the 3 biggest categories (Best Picture/Actor/Actress) from 1927 to today. He makes a strong argument for a 1945 win for Joan. So why wasn't she ever nominated for any of her film work? It may have to do with the fact that her husband at the time, producer Walter Wanger, was also president of the Academy of Motion Picture Arts & Sciences during most of the 1940s, when Joan's film career was at its peak. If she were nominated, there may have been questions of nepotism and conflicts of interest.
Bear in mind that Bennett wasn't associated with a studio at the time. The studio system had its definite disadvantages, but at the same time if you were an actor under contract to a particular studio, the studio had a vested interest in promoting your career. That would include things like campaigning for you in things like the Oscars. Also when you look at the competition for the years in question...these are (and I adore Joan Bennett) but these are A List, bonafide Stars with a capital S. You've got Greer Garson (3x for those years), Ingrid Bergman (2x), Jennifer Jones, Gene Tierney, Joan Crawford, Bette Davis (2x), Claudette Colbert, and Barbara Stanwyck, Joan Fontaine, and Olivia de Havilland. Most of those women were under contract to major studios and the films in question were mostly big, big movies with star studded casts and A List directors.
I'm not denigrating Wanger, Bennett, Lang, Robinson, Duryea, or any of the other creative forces in those films, but I don't think they stood a snowball's chance in hell of making it to the Oscars--which ultimately aren't that meaningful as a measure of quality.
We also need to consider that what we call film noir today didn't really exist as a genre--these were considered crime pictures. There wasn't a lot of cachet to being in one of these.
Also Wanger was an independent producer and not on the same level as Selznick. That's part of the reason why the films Bennett made with him are either not released or exist in poor PD prints only. His arrangements with studios and distributors were apparently complex beyond the telling. Trying to untangle the copyrights is, I am told, involved.
I've got the Kino release of Scarlet Street on my Christmas list. Now if they would only remaster and release Reckless Moment, I would be a very very happy camper.