Some conquerors were very protective of the Art that was present in the areas they had taken over. Alexander the Great comes to mind. As do the Mongols. The Romans didn't routinely destroy the art work of conquered people.
I think the worst were communist and socialist conquerors. Hitler, Stalin, Pol Pot, etc, etc.
I think (just my theory) that it's because they have no art of their own. communists produce -- Nothing. At all. They are like locusts, they feed until there is nothing left, then they go underground. Hitler was a socialist. Despite the attempts by contemporary socialists to disavow him -- He was a socialist. Period.
At least the German socialists, while they had little in the way of actual art, were good Engineers.
Our current occupying socialist conquerors pro tem are completely without imagination or art. They think 'art' is putting a crucifix in a bottle of urine. How divine.
So, being without art or imagination or measurable IQ's, all they can do is destroy the artwork of others.
They make noises like the art is objectionable but that's not the reason they do it. They are devoid of character, curiosity, inventiveness and artistic talent. All they know is destruction of others' property.
Which tells me -- They won't last. Those types of conquering tribes never do. Never have. Never will.