OK I will castigate you for being a cynic.
"I just tend to be skeptical about the basic sci-fi protagonist, who is perceptive, dedicated, fearless and hyper-competent, all the time. "
I just finished reading Hail Mary and I agree with Rob's comment below: the story really was FULL of instances of human mistakes, shortcomings, failures. Like The Martian, it was a story about persistance and problem solving, while occassionally doing very stupid things. It was a story about a coward who becomes a hero, even when there was an easier path. And I always love good redemption stories.
Perhaps the communication between human and alien was too "easy". And to me the Astrophage life form seemed too implausable. Nonetheless, it was science FICTION on an excellent level.