After 1909, Monet drastically enlarged his brushstrokes, disintegrated his images, and broke through the taming constraints and delicacy of Impressio… - Jerry Saltz

The elephant in this big room, obviously, is context. In America, the twenty-first century began with the contested election of 2000, followed shortly thereafter by the terrorist attacks of September 11, 2001. From there came the wars in Iraq and Afghanistan, the financial collapse of 2008, the lightning-rod election of the first black president, the rise of antidemocratic authoritarianism at the hands of his successor, and finally a second contested election and a worldwide pandemic that saw the death of one million Americans. All of which is to say: None of the art made in this period happened under “normal” conditions.

All art is a kind of exorcism. This is what gives art its power to change the conditions of our life.

You can't prove Rembrandt is better than Norman Rockwell - although if you actually do prefer Rockwell, I'd say you were shunning complexity, were secretly conservative, and hadn't really looked at either painter's work. Taste is a blood sport.