Of course that is true. I'm not suggesting otherwise. Ravel failed at the men's level at age 18-26. I'm just saying that performing at that level isn't a guarantee to being the generation's best talent. There might be other players who when they grow physically have all the tools he has and thus end up as good as him, but we wouldn't know that right now because that kid at 16 is physically competing with adults. Just imagine him at youth level competing against kids.
At the same time, he could just be physically superior to most talents even when everyone is an adult. Mbappe is one of those kind of talents as was Brazilian Ronaldo.