Wax isn't
harmfull to humans, fish, etc. if that is what fabric softener is.
In fact it aids digestion. Bee's make it and thrive on it. Our ears even need it to keep them from being too dry, too wet, and it wards off infections.
Nothing wrong with saving some fresh water, because aquifers in certain areas are low or even dry. Removing phosphates from detergents had nothing to do with saving water. Phosphates can make too much algae grow, or the wrong type, which harms other biological species of plants or animals.
The best solution to pollution is dilution with clean water, so the more clean water there is, all the better for diluting.
If alkalines, corrosives, or other non inert chemicals are added, that may be a problem. Solutions are alkaline, and base. They must be balanced. Too much pool chlorine makes a pool too alkaline. It needs balance of base and alkalinity so the calcium base isn't too low. Otherwise the water will make calcium leech from the gunite concrete to balance it. It can also remove body hair and healthy skin cells. Salt water is a better modern pool filter medium than bromine or chlorine.