One of the definitions of sophisticated is “having a refined knowledge of the ways of the world cultivated especially through wide experience.”
Approaching any situation or task from a variety of perspectives invariably gives one the ability to more fully understand and engage with it.
When approaching the job of designing something with the ability of multiple perspectives, which one might gain with a “refined knowledge of the ways of the world cultivated especially through wide experience,” with an eye towards simplicity and straighforwardness, the result can perhaps be deemed to be “sophisticated simplicity.”
It is the kind of simplicity that comes out of the process of wittling down a thing that often times is by nature quite complex, by considering many of the factors, issues, possibilities, opportunities, ramifications, desires and needs involved.
And doing so with the kind of style and taste one might also accrue with “refined knowledge of the ways of the world cultivated especially through wide experience.”