I have a handful of abstract urinals to remind me of exactly this perspective. It’s a very strong position on the question, as I see it. That’s a long winded way of saying: precisely, glad you mentioned Duchamp’s urinal.
I do think the answer to the question of what is art has something to do with using a human mind to create a shareable experience (incl. visual representation or tangible object). I believe the gardens at the historic plantation houses near me are art, but probably less so my neighbors dual flowerbed / produce garden. If the output of the process is entirely functional, I don’t think it’s art.
clarifying this would require more words and thoughts than I can come up with at this moment