Some people have terrible water from private wells. They do have a good reason to use RO water. Few others do, unless they are really intent on breeding a few selected species of fish. Just for normal aquarium use, almost all public water system tap water is fine.
But, your question was whether you have to do big water changes if you use dry chemicals for fertilizers. The answer is no, you don't, unless you are following an Estimative Index type of fertilizing program. That method is based on dosing a bit more of each fertilizer than the plants really need, which could cause an excessive buildup of some of the nutrients over time. To avoid that we replace about half of the water per week, getting rid of any excessive nutrients.
You can also get and calibrate some good test kits, and use them to monitor the level of each nutrient in the water, so you can adjust your dosing and not over dose at all.
Or, you can use one of the lean dosing methods, where you dose less than what the plants need, and accept the slower growth and possible problems that can be caused by that. No doubt at all, the Estimative Index method is the easiest to follow, but it does require regular big water changes.