The simple answer is convenience. Every faucet, sink, and plumbing fixture in your entire home will provide you with a clean and healthy supply of water. This makes it much easier to perform simple tasks around your home, whether it’s cooking, cleaning, or bathing. Potable drinking water has become something of a luxury because over 85% of municipal water supplies contain either hard minerals or some sort of contaminant.
Also, municipal water tends to be heavily-chlorinated which can render it undrinkable. Other contaminants that you will commonly find in water supplies include lead, mercury, and industrial solvents used for cleaning and lubrication. It’s pretty much inevitable that toxins, bacteria, and other contaminating elements are going to make their way into your water supply.