I've found it can be easier to manage what you have installed, since you can just look at that list and go "oh, why do I still have xyz installed, idek what that does anymore"
While it sounds sexy and attractive... Not sure the amount of time needed to configure your NixOS is worthwhile. (Except if you have time to spare and want that learning experience !)
Just put everyhting In your personal notes and you have a similar "feature"?