Don't you have the same problem with the salt that you have with the water, no way to tell what dose everyone is receiving?
https://www.paragonwater.com/does-reverse-osmosis-remove-flu...
The latest generation of small under-sink reverse osmosis filters claim to waste only 1 gallon for every 2 gallons of usable water. Still bad but much better than before.
After years of RO water I switched to spring water due to health issues and I will never look back.
Of course, it is insanely expensive to drink 3L of spring water and so frustrating to not have unpoisoned water from the tap.
Also relying on municipal water for mineralization is a bad argument. The minerals in water supplies is highly localized, or drinking tap water could leave you deficient in one or more minerals depending just depending on where you live.