Unless you have something to remove nitrates in the water column, water changes will always be part of the hobby. Drip systems that slowly change water out drop by drop are popular and provide your “stability” without “water changes” but they are not super easy to set up for a smaller system. They are more useful on large tanks/systems. Still, the waste goes somewhere and the beneficial bacteria have to be disturbed and renewed every so often in order to keep your stability. Closed system tanks are ticking time bombs unless super lightly stocked and super heavily planted. Even then you run into issues. Once you think about it, you’d spend more time coming up with a way and preparing a tank and maintaining/tweaking the tank to not have to do water changes than you would to just do your water maintenance.
As per 50% water changes, most people agree that smaller 10-20% water changes are far less taxing on the fish, but you have to do them more frequently, so do you stress them out more times per month but for shorter periods of time or do you stress them less times per month but for longer periods of time? It’s all a cat and mouse game.
6 of one, a half dozen of another.