Water pitchers fail to remove heavy metals. Groundwater supplies in mining areas often have lead, arsenic, and even trace amounts of mercury. The day any Brita can make briny tap water taste good for coffee, is the day I will fall over.
The store where I am connected, has ten or so Brita pitchers. Locals (Mexicanos) do not trust them and all ten have been sitting on the shelf since they arrived.
Rural water systems often loose pressure to leaks or to pumping shutdowns accidental or intentional. In many cases you do not want to know what leaks back into an empty water pipe.
Some cities have purified water supplies. Me? I carry a Total Dissolved Solids measurement pen. Reverse Osmosis plants have been known to pass less than 100% sanitized water.
Many areas have so many minerals in the water supply it raises the devil with hot water heater anodes. I've seen folks dumping 19-liter purified water garrafones directly into their rig's water tanks. Chlorine purification cannot see a reverse osmosis membrane so count on city water being untouched well water.