ValveSoftware maintains an [udev rules repo][1] to help downstream distributions. `steam-devices-udev-rules` is created from that, and contains only udev rules. The udev rules contents are the some as `steam-unwrapped`. `hardware.steam-hardware.enable` option is also useful for apps like `cemu` and `rpcs3`, after this, it can be enabled without enabling `nixpkgs.config.allowUnfree` and installing `steam-unwrapped`. [1]: https://github.com/ValveSoftware/steam-devices