I think he, like many other superstars of the great piano age, simply wasn't known to be a musical innovator.
Many of the greats had their performing equals:
Mozart and Clementi,
Beethoven and Hummel,
Liszt and Thalberg,
Chopin and Dohler,
Schumann and his wife Clara.
But while they were equalled in playing abilities or even reputation, they are remembered more for what actually lasts beyond the grave: their writing skills.
How far they went beyond the conventions.
Being popular makes you known by your generation; being different makes you remembered by the next.