Copper: Impermeable, long-lasting, and durable
Impermeable - Unlike PVC, copper is completely impervious and keeps unwanted or dangerous chemicals from contaminating the water supply. Copper can withstand freezing, thawing, and other disruption far better than plastic alternatives, meaning your work will last longer and perform better.
Long-lasting - Copper is an incredibly well-known material, meaning professionals can accurately predict the longevity of copper in a multitude of different scenarios. Unlike plastic tube, which is prone to leak, rupture, and crack over time - copper will continue to perform for decades to come.
Durable - Not only is copper highly corrosion resistant, it can also withstand UV exposure, contaminant exposure (chlorine, chloramines, etc.), and weather events far better than plastic alternatives.