There is a distinction between being useless and having no utility. I
content that art has no utility in that it does not have "the quality
of being of practical use" (the meaning of the word utility). That
does not mean that it is useless.
I agree that there is a subtle distinction I had not considered!
Is art useless? That is another question and not one that I was
addressing. Given that in around 6 billion years the sun will turn
into a Red Giant and all life on Earth will be eradicated then you
could view all human endeavour as useless
Aye, you're right: it's another question. I have my faith in humanity
(or what it may become). In 6 billion years we might be symbiotic with
novae. 