Chess isn't like most sports so it's hard to extrapolate from them. The existence of ELO in and of itself doesn't help explain whether the super youngs are competitive at the highest levels unless you are saying they should be manually looked up, and you didn't say any of that so it's ridiculous to treat that like it was implicit or an obvious logical inference.

And they were right that "a lot of really strong players are 12 years old" doesn't by itself help clarify where they are relative to elite competition at other age bands let alone clarify what age band perform bests at the end of the day. Even now I still don't understand how "a lot of 12 year old are good" is to supposed to answer that even implicitly. If anything the natural reading of that would be an implication that they are among the most competitive, yet your elaboration says the opposite.