Your implicit claim that consumption is jusified by the fact that it is consumed is wrong. No good or service can bring happiness. The only consumption that is justified is that which is nessesary to live or improve general well being such as food, shelter and medicine. Other goods, such as art, are a distraction from life.

>More importantly, art can be an end to itself.

Is life itself not the greatest art? One who lives for art is already dead.

>The idea that everything has to be a means to some end can devolve into treating all human endeavors as inputs into some global maximization functions

Even if all basic needs were fulfiled, art still would not have true value.

>reducing humans to cogs in a machine

Are artists and thier consumers not cogs in a machinine maximizing their pleasure? Not that this framing means anything on it's own.

>That feels a bit philosophically bankrupt

Many philosphies have taken the stance given above, begining in ~500 BC in Buddhism, and reappearing independently multiple times such as in Mohism in 400 BC and still existing in modern philosophies such as some forms of utilitarianism and nihlism. No serious philosphers, meanwhile, beleive that the meaning of life is to look at art.