There are a few points here that people are getting strangely abrasive about.
I have never had chloramines, and always chlorine. In a run of the mill tank, you can gas off the chlorine by pouring the water into the tank with force. The chlorine will dissipate.
I didn't use dechlorinators for many years. I use the API stuff now in certain tanks, because I found with the gas off method, breeding was affected for a couple of days after a water change. Given that I water change tanks weekly, 4 days a week was not good for egg collecting.
Most of our disagreements come from the devil being in the details we forget to mention or take for granted.
So I dechlorinate all tanks in which I hope for breeding, for all species and groups. Most hobbyists don't breed fish, so
@plebian 's point is one I'd agree with. Almost. Mostly. Not always.
20% is better than nothing, and is a basic level that works. I prefer more, even in lightly stocked tanks. If I go beyond 30%, I dechlorinate in all tanks.
Source water IS crucial. Some of the water out of taps in rural farming areas is awful stuff. The water table is polluted in a lot of places. How people in those regions manage their water is radically different from how I would. My water comes from a protected watershed and is very clean. I know that's a luxury, and I sometimes catch myself up when I post here because I do try to remember I'm fortunate.
The internet is what it is. If you state something and back it up, you're accused of being too serious, and going on and on. If you state something and don't back it up, you have no credibility and could be passing along myths.