In the 1920s we had the end of war, in the 60s the end of poverty, and in the 80s the end of history. Stupid predictions never cease.
I'm sure that in the 1890s and early 1900s when most of our grandparents were heading here on 'Banana Boats' speaking strange languages and practicing different religions, some Victorian version of Buchanan was spouting the same nonsense. If I'm not mistaken, the percentage of 'foreign born' citizens was much higher then than now.
Xenophobia is always good for making a buck. There will always be a market for it.
But it did end. Most of the "art" we see produced now is pop art not high art. Piss in a vile with a cross thrown in it etc...I'm around a lot of "artists" and most of them are really crafts people not artists.
Oh sure, art is alive and well if you enjoy viewing crucifixes in urine or multiple images of soup cans.