Not everyone aims at Stanford, though, and indeed that wasn’t the original question.
And plenty of kids at my daughter’s school did more than one year of an art and got into T20/T30/T50 schools. Her school did not have a religion requirement or music (in addition to an art) or classical language or the various other possibilities named above so yes, that’s also something to take into account, that plenty of schools do actually have a rigorous curriculum that still easily allows for more than one year of an art.