Fair point) It really depends on how you use your system. If I weren't constantly tweaking things, I don't think it'd be an issue for me either.

In my case I also use Home Manager as a NixOS module, so every home config change is a system rebuild too, and I'm at almost a thousand generations by now. When I'm trying out something new I can hit up to 50 rebuilds in a day (rare, but it happens), and that's exactly when it becomes a problem.

So yeah, for a lot of people this is definitely overkill, but for others (similar to how I use it) it can save a lot of digging.