Saying "simple system" is like saying "teacup"; what kind of tea, what temperature? Are you pouring right after steeping or after cooling? Does it have a handle

Saying "simple system" is like saying "teacup"; what kind of tea, what temperature? Are you pouring right after steeping or after cooling? Does it have a handle and/or saucer? Is there a ceremony or cultural aesthetic involved? Do you want it to develop a patina? Is it used for more than one kind of tea? Why must we operate systems? Entropy, for one, but also because simplicity is relative.