A couple dollars saved is always worth it

electrolytes are not just salt

Except for first world countries. But tap water has chemicals in it so you don't get the nutrients or minerals of spring water. It also has chlorine, which is harmful when consumed in large amounts.

I live in a country that has the best water quality in the world, we don't have chlorine and chemicals in it is and it is spring water in our taps

Most people don't have access to spring water and have to get it pumped in from reservoirs. Reservoirs are a living ecosystem and must be cleaned before consuption otherwise the water could kill you. Chemicals aren't pumped in for shits and giggles, they're added so people don't get poisoned. The trick is to balance everything to make the water as safe as possible without going overboard. I don't mean to come off attacking you, but spring water is a rare treat in most of the world and chemicals are a necessity to clean all other water.