Glad you mentioned “Étant donnés” a fascinating and thought-provoking painting.

I would argue Bicycle wheel and Rotarary Demisphere are art. Duchamp may have said they were not meant to be, but he also said “Anything is art if an artist says it is” and he certainly didn’t have any issues with displaying these objects as art. After all, he remade Bicycle Wheel three times and bothered to give the sculpture a name. Furthermore, considering Duchamp’s involvement with Dadaism (where art is not art, but rather a protest), and Fountain (a Dada Redymade) and one can logically extrapolate his “Precision Optic” pieces are meant to be art.

Plus Dadaists are known for speaking bable. If they were willing to say “anything is art” what would stop them from saying something is not art. In my opinion, Duchamp’s LHOOQ is saying just that.