Hmm, why is it so important to "finish" a side project? Can it not be something that you work on whenever you have time, for many years? As long as there are us

Hmm, why is it so important to "finish" a side project? Can it not be something that you work on whenever you have time, for many years? As long as there are users, software projects are rarely "finished" completely. I just released the first public version of my first real side project [1] and I don't expect it to be "finished" for years. I have so many ideas for the domain and I am sure new users will bring continued input. Are there popular examples for successful side projects like this? [1] https://keycombiner.com https://keycombiner.com - a web application to learn and train keyboard shortcuts