"Ganga is so pure, it's literally impossible to make it impure and it has capabilities to wash off all our sins, then how can it possibly be polluted by people bathing/washing their cloths in it?"

I tried making people understand, the only way we've forward is making movies which show what can happen if we don't stop these activities then it will begin making sense to people who have no education background.

Hindu religion is not like Catholic Church. Unfortunately, in such issues, it is very fragmented and 'decentralized' with multiple different sects, castes, pontiffs etc.

Uttar Pradesh, where Ganga mostly flows has a lot of water heavy low-tech businesses. Leather tanneries is the first thing that comes to my mind. Illiteracy doesn't help either.

Things are changing. Ganga in Varanasi and a few other areas are much cleaner in the last couple years than they have been in the past!