Dashiell Hammett & Patricia Highsmith are, I think, still underrated masters of depsychologized characterization.

Hammett's protagonists rely on projecting confident competence to cover inner confusion: "Red Harvest" in first-person, & the third-person narrative voice of "The Glass Key" anxiously searching every character's eyes for meaning.

Highsmith's protagonists repeatedly find themselves acting in ways they can't explain to themselves, usually with tragic results. Untroubled impulse-surfing Tom Ripley is an exceptional success, as is the protagonist of "The Tremor of Forgery", an answer-novel to Camus.

As you suggest, there's often overlap between mysteriously-motivated central characters, mysteriously-motivated authors, & mysteriously-structured narratives, as with Beckett & Robbe-Grillet. Like you, I think, I'm drawn to all three tendencies.