What if everything is an illusion and nothing exists?
In that case, I definitely overpaid for my carpet.
(Woody Allen, Without Feathers, 1975, 10)
That’s basically all that needs to be said re all kinds of ›Realisms‹ that popped up in the history of philosophy―from ›ontological‹/Platonist realism via the medieval Universalienstreit to the so-called ›Structural Realisms‹ which are so en vogue today, but only push the ontological bump in the rug around.