Game theory is ridiculous. The first acquaintance with main “solution concepts” usually produces a question “wtf?!” in a man with a good common sense.
Good economics approximates essentials with assumptions to overcome limitations of verbal reasoning. Assumptions in game theory mostly exist to confuse readers without really saying anything that matters.
I believe those are not assumptions but conventions and the only question that a man with a good common sense should be trying to ask is “why so many individually silly things when come together say so many astonishingly amazing stories?!”