you don't have to have a RO filter to remove chlorine/chloramine. I am planning on getting this under-sink filter:
https://www.homedepot.com/p/Aquasan...aucet-in-Brushed-Nickel-THD-5300-55/301782806 it removes chlorine and chloramine, many pharmaceuticals, and also has a prefilter to reduce TDS slightly. It doesn't waste as much water as RO units do, so depending on the cost of water for you, the math may make this type of filter (replacing cartridges) cheaper than paying for the water than goes down the drain with an RO unit.
Regarding convenience of water changes, I guess it depends on your definition. The most convenient way of doing a water change is to have a python or similar system hooked up to your tap, pre-treat the entire aquarium with chlorine remover, and then run the water directly from the tap into the tank. There are various opinions on whether that is the best for the fish, since they get a higher dose of dechlorinator, and may be exposed to chlorine briefly before the dechlorinator takes effect.
The next most convenient way to do a water change is to use either an in-line filter from your faucet or a small holding vessel you run water into "real-time" from your filter that you then pump or gravity feed into your aquarium. In this case, you don't need to pre-treat your water at all (Assuming your filter removes chlorine), but you do have the hassle of figuring out how to get the water into the tank, since often the water pressure after the filter is not enough to get it all the way to the tank.
Third most convenient is to prepare your water in holding containers ahead of time. Some folks even have heaters in their holding containers so that they can temperature-match with the tank. The benefit of this method is that after sitting for 24h, the water parameters in the "new" water have stabilized (co2 dissolved has off-gassed etc), so you can test for the parameters of the new water and compare to the old water, and if necessary, wait another day before starting your water change if you need to add anything (like peat, lime rock, etc) to adjust the hardness or pH.
All in all, going back to what
@essjay said, it really depends on what kinds of fish you keep and how well their water requirements match the water coming out of your tap. if you keep sensitive species that don't match your native water well, then you are almost by default stuck following approach three, but if your fish are more hardy and better suited to your native water source then approach 1 or 2 may work just as well.