Anyone who has practiced any discipline, and tried to achieve in that discipline, will recognize that talent exists. It's so obvious I don't know how this person can not believe in it.

Practice isn't about hours alone, quality of practice matters as does what you do outside of practice. Just because a kid is locked in a room with an instrument for an hour doesn't mean they're actually practicing for that hour nor does it mean it's the only hour they're practicing.

The reality is, one person critically listens to the pieces all day long, taps the rhythms with their fingers while they're standing in line at the store, and plays for the fun of it every time they have free time, while the other who "put in the same practice hours" leaves their instrument in the practice room and doesn't give it a second thought until their next scheduled rehearsal.

When you get to the point of a second chair vs a first chair in a high profile professional orchestra, sure genetic things like length of fingers and forearms may have the slightest impact. Just like when you're comparing one Olympic runner to another that's only 1/100th of a second faster.

But saying that someone else is "just more talented" is usually just a way of saving your own ego while giving up because you don't want to put in the effort to get better. It's a form of "sour grapes".