Yes, Duchamp originated many of the approaches to art that are now common. (Most of them, probably!) I can't think of another artist that changed art so radically in such a short time in a way that 'stuck' for so long Anything Modern or Post-Modern owes a lot to Duchamp.
I remember, many years ago, reading an article called something like 'Marcel Duchamp and the End of Art' (if anyone reading this knows that article / paper, or where one may find it, let me know) which basically ended-up meaning, Duchamp and the beginning of what we now know as 'art'...
BTW: I made an installation that was definitely homaging Duchamp's Fountain and here's a brief summary about 'In Lieu (of All We Are)' :
