Yeah i get that, but also it has some huuuge problems. A very large part of arch users rely on the aur which is horrible from a security standpoint and in general for usability. If arch made its package distribution better it would be a really solid distro with a lot of merits. Of course if you get arround the package management woes its a good system to use. As for nix you dont actually re-build your system every time you change something cause you also do that technically when you boot, tho not in the sense of building software from source, it just links everything so its accessible.