There will always be one superior build.
The questions are how easy it is to find and how far ahead it is of other builds.
With Google (and now Google AI), it is extremely easy to find. And as @Aulis says, it then becomes very boring to play the game even the first time, let alone replay the game. As much as I dislike DnD mechanics (for very different reasons), the one awesome thing it has going for it is its classes system whereby you can make and play a huge range of different characters all of whom are (roughly) equally viable and fun to play.
LLMs can only regurgitate what is written in their training data. So unless the best build is obvious and people agree on it AI will only tell you who shouts the loudest.
Ideally there will be several builds that all perform similar to each other so thats either impossible to tell without a mathematical model which one is really the best, or that the best build is only a slight upgrade over other builds, instead of it being so much more powerful that everyone can instantly tell it is the best build.
