It's obviously not true in a world with nuclear reactors. In fact, widespread use of nuclear would make hot water cheaper for everyone and greatly reduce waste

It's obviously not true in a world with nuclear reactors. In fact, widespread use of nuclear would make hot water cheaper for everyone and greatly reduce wastewater production - used water (even sewage) could be distilled into clean water vapor and dry, sterile biological matter with enough clean energy. Then we just need to add some minerals back into the water to make it perfectly tasty and healthy to drink.