Why does some coastal cities/counties have a problem of lacking drinking water?

Question

Like California and South Africa, isn’t the principle of water distillation relatively easy? evaporating from one end and cooling it from the other so that it becomes liquid again, leaving all the salt and pollutants behind.

In: Other

Answer 1

Side note, it is being used

>An estimate in 2018 found that “18,426 desalination plants are in operation in over 150 countries. They produce 87 million cubic meters of clean water each day and supply over 300 million people.”