Everything about your OS is defined in a config files and can be rebuilt. You break something you don’t need to do a complete reinstall if you can’t figure it out. Just rebuild the last working configuration. Sharing builds with your friends is easier.
For gaming getting your graphics card going is much simpler. I never had steam and proton games run as well as they do with they nixos defaults
Basically but it’s better, nix has a unique way of doing the underlying the logic which as is own benefits. Also since nix is not a container it doesn’t have any of the speed penalties that come along with that. Since nix is functional as well, it means all operations can be undone. So where you might te build a docker image from scratch or by using a A/B system like other immutable distros it allows nix to just modify the system while it’s running with minimal side effects.
nix has a unique way of doing the underlying the logic which as is own benefits.
Honestly, this is what I like least about it. I do not like unique, single-purpose Domain Specific Languages. To me, requiring use of a DSL that is not like common languages used for similar purposes is a major detractor.