Sourdough for breakfast

We used a commercial-made starter for this Sourdough Bread as the real thing takes about three days to make. That, in addition to water, strong baker's flour and yeast is proofed and baked for 30 minutes. I won't lie - it tastes good, but I don't get why you'd spend three days making this. I think the 'Art of Bread' is lost on me sometimes!