Chlorine is added to kill harmful microbes in the water. It’s there to treat the water, not the drinker of the water. See the difference? It’s important.
Yes chlorination of water has been beneficial (although it’s not the only alternative for water purification) — but, it comes at a cost. Compounds of chlorine in treated water are proven carcinogens. I filter the stuff out of my drinking water. If you do some research on the topic, and give it some thought, you’ll probably make the same choice too.