They went from being THE banana for much of the western world to being extremely rare as in available on a few farms in Florida & Hawaii and Asia. I was inaccurate in saying they were all wiped out.
you can buy either the Gros Michel or a very similar variety in Chinatown and Flushing in NYC. And the local green markets have several other varieties as well. There are definitely other bananas around, most people just don't care that much.