The aquasafe water balance does work
The evidence for this stuff is pretty sketchy. There have been several detailed threads that go over the stuff, search function should find them pretty quickly. However, I will re-write one of the best examples of the harm something like the EasyBalance stuff will do: A member set up three tanks with guppies. One he did his usual waterchanges and maintenance, one he just left alone, and one he used the EasyBalance per the instructions. They all got fed the same, same lighting, etc. as much as possible. The tank with the usual maintenance was very healthy, the guppies spawned many times and he had a tank full of fry after 6 months. The one where he did nothing -- no water changes, no maintenance, also was pretty healthy, the guppies spawned a few times. Not as much as the well-maintained tank, but still pretty normal behavior. The guppies in the tank that used EasyBalance never spawned once. Now, guppies are the rabbits of the aquatic world, if they are not spawning, something is wrong.
Obviously, this is only one single example, and isn't conclusive, but I also don't know of any study to conclusively judge the product.
Ultimately, getting new water is gold standard, there is nothing that can replace that. The fish will be so much healthier. And, it is so much closer to replicating nature. That is really why I keep an aquarium, to try to bring a little slice of nature into my home. Water changes are at least attempting to mimic the conditions in nature, they certainly aren't close, but they are much closer than dumping a bottle of chemicals into the tank.