Here's one reason: Why isn't NOTORIOUS on this list, to say nothing of a high ranking?
Bergman is not merely allowed to be, she is asked to be (and she agrees to be) a sexual partner of a presumed Nazi in order for something like the OSS/CIA to get the good's on her husband's associates.
As for quality, well, it's one of Hitchcock's masterworks.
For my money, this is one of the most adult films in the classic Hollywood era (to say nothing of the classic noir era) -- meaning it's a serious, complicated study of a love relationship and a biting exposition of "for reasons of state."
Could other spy noirs be recommended? Sure, but on the Blackboard I see no reason to do so.
In a different vein, despite its title now lodged firmly within the English language, I would never have presumed on the Blackboard to raise a toast to GASLIGHT. As the British might say, such things are just not done.
Could other women in distress noirs be recommended? Sure, but on the Blackboard I see no reason to do so.
That is why, way back when, seeing my disconnect in advance from the Blackboard, I opted out of listing top drawer noirs that were outside the hardboiled paradigm, which has been so heels-dig-inly represented thus far.