not always true, Randomness is a factor in AI. However, if your attempting to create perfect ai, randomness should only be used when there is multiple ways of doin somthing, and all solutions have an equal number of positive factors, making one emthod no better than the other. In this case you should either choose the fastest exectuing, or pick a method randemly, watever.
In a more human attempt to create ai, you will possibly have all the methods you can use to achieve somthing, however, the randomness will be far greater. You wont always want the best method to be picked.
So randomness is very much used in ai.