Things can be obvious if they are simple. If something complicated is obvious, such as anything that anybody seriously studies, then for it to be simple you must be abstracting it a lot. When people find such things obvious, what they often mean is that the abstraction is so clear and simple its implications are unarguable. This is answering the wrong question. Most of the reasons such conclusions might be false are hidden in what you abstracted away. The question is whether you have the right abstraction for reality, not whether the abstraction has the implications it seems to.
Abstractions are essential to understanding, but we must keep in mind that abstractions ignore information. Essentially, they are storytelling, organizing raw data into actors and relationships while leaving out the irrelevant stuff. When too much stuff is deemed irrelevant, the narrative becomes obvious, but the abstraction may become mostly fiction, too removed from the raw facts.
I still remember my freshman physics professor at Rice warning us that real atoms were not anything like the Bohr model of the atom, but that the model gave great answers for a useful set of questions.
With humans, it is all storytelling.