That headline is an often referred quote from Lella/Massimo Vignelli. And I … sort of agree. There’s always more to it than meets the eye. But in the sense that design is all about solving problems, then, yes. If you can design one thing, you can design everything. The skill is to know how to solve a problem. What perspective to take into account. But some design related professions require more knowledge than others. And where does design start and where does it stop? So yes … and no.