There may be the need to make a distinction between being a child performing prodigy, and being a compositional prodigy.
Agreed that his earliest stuff is merely ‘good’ to ‘very good’, but we don’t know how good of a performer he was at that age, relative to the standards of the time.
A lot of the ‘tricks’ his father had him perform could be done by any musically gifted child. Mozart is remembered for the great music he wrote as an adult.