You can say that design has lost its value when the function of things disappears. From a different perspective you could also say that contemporary design is not talking about function, but takes this for granted. It is the approach; mental and emotional function that counts and if this means physical functions will disappear this is not a loss but a change. A change in the function of design, offering a service to design services.
E.g. you can make a chair, but what do you want? I guess it’s made to sit on it, so what is the design? In this case the design is purely based on a visual approach. If you would make a chair to communicate a story, opinion, statement, the visual of the chair gains a function that can be more interesting than an other object to sit on although the relation to a recognisable object like a chair is valuable.
Is it functional to make a functional object instead of an object without physical function but an approach to communicate?