The end comment about the blank canvas by Rauschenberg reminds me I saw a similar blank white canvas in some museums modern art exhibit years ago. I have no idea who it was by. Might have been Raushenberg for all I recall. The thing is any of us could have done the same with a can of white paint and a paint roller if we wanted to actually paint the canvas. There is the very very rare modern art piece I come across I like but I find them more amusing than true works of art. The vast majority are worthless IMHO.
In college, my 2nd semester Art History final included a Jackson Pollack "painting". I refused to simply regurgitate the nonsense the professor had spouted about it in lecture, and instead wrote an essay saying that I found it laughable that anyone actually considered Pollack's work "art". I got a "C" in the class, mostly because I probably got a 0 on that final exam question. But it was worth it. After two semesters of Art History, where we looked at some of the greatest masterpieces of painting and sculpture from the Greeks up through the Impressionists, I just could not bring myself to give Pollack's paint splatters any credence.