There are exactly three games where I could run it as-is, from the book as written, and not be tormented by the screaming of the mod and homebrew gremlins that live in my body. This is not only one of them, but the one that also feels both the most complete (looking at you, Anima: Beyond Fantasy) and has the setting feel right in a way that does not beg me to try and drag out the maps and notebooks for another homebrew world (looking at you, Pathfinder 2e)
It says Beta, but frankly this game is better designed than most of the big name games collecting dust in my library and could be sold as-is right now.