But if we are to go more interesting places... shouldn't we have down breathing, eating, and sleeping on the moon so well that it isn't much of a cost or a risk

But if we are to go more interesting places... shouldn't we have down breathing, eating, and sleeping on the moon so well that it isn't much of a cost or a risk? It's inherently a good testing ground for things we need to do reliably much further later. Imagine if we never built ISS because putting a space station in Earth's orbit was a solved problem...