What does it matter if it's more efficient or not? I want to drink clean water today, I get a gallon delivered to my home.
Also, when comparing prices for necessities, the only thing that matters to an individual is the actual amount, not any percentage comparison. You've fallen into a mental trap that I've seen a lot of people fall into, by comparing prices by percentages. If most people in a developing country can easily afford clean water delivered to their homes, then it doesn't matter if it's percentage wise more expensive. Same thing if you buy some ramen noodles. It doesn't matter in the slightest if they cost 50c or $1.
Also, when comparing prices for necessities, the only thing that matters to an individual is the actual amount, not any percentage comparison. You've fallen into a mental trap that I've seen a lot of people fall into, by comparing prices by percentages. If most people in a developing country can easily afford clean water delivered to their homes, then it doesn't matter if it's percentage wise more expensive. Same thing if you buy some ramen noodles. It doesn't matter in the slightest if they cost 50c or $1.