While naming someone "the smartest human ever" is foolish and clickbait in itself (it apparently worked), being very good at solving a completely man-made problem that have already been solved, via machine brute force, is hardly justification for being crowned "the smartest human ever".

In a sense, Mr. Carlsen playing chess is no different from a circus juggler, except that he juggles with his brain instead of hands.

A person worthy of "the smartest human ever" needs to make breakthrough in problems that have NOT been solved, either by machine or human. There are many such individuals throughout human history who fit this criteria (otherwise our civilization wouldn't have been advanced to the current level), and there are a lot more contemporary humans doing the same. They have a better claim to the foolish title than Mr. Carlsen.