To say that math has to be useful is like saying the English language is only good for ordering pizza.
Pi is a cosmic mystery. How about home-made Pizza Pi instead? Photo is how I like my Pi - not exactly round according to Pi but rustic, and slightly burnt in an outdoor wood-burning oven. Goat cheese, pancetta, a little asparagus? Why not?
With some beer. Note that they are using Pi to try to find that missing airplane. Pi is handy.