Yeah, internal logic and consistency are important. Essentially if your world is functional within its own terms, the story tends to write itself. Because, you know, logical things happen when characters are set in motion and plots play out. This is what many people don't understand whey they say of fiction "lol it is made up, why does anything have to make sense."
I think good authors do a lot of thinking and world building that doesn't necessarily end up on spelled out on the page. It informs the story and the characters, and I do believe readers appreciate the sense that characters exist in a functional world and have reality to them. But it's a subconscious appreciation. It doesn't require pages of exposition to explain, but when it's missing from the mind of the author you notice it.
To me the best fiction provides just enough to get the reader involved to the point they begin speculating logically on what's happening between the lines, because there's a well constructed foundation that invites such consideration. That's when the story becomes real to the audience.