> They don't really ever show a sense of "hey, I've got a thought, maybe I haven't considered all angles to it, maybe I'm wrong - but here it is".

Have you ever read Scott Alexander's blog (Slate Star Codex, now Astral Codex X)? It's full of doubt and self-questioning. The guy even keeps a public list of his mistakes:

https://www.astralcodexten.com/p/mistakes

I'll admit my only touchpoint to the "rationalist community" is this blog, but I sure don't get "full of themselves" from that. Quite the contrary.