When I was in high school I was really into math. I was way ahead of my year group and I figured it was more interesting to do special problems of the "what is the last digit of 2^2022" variety, the kind of thing that didn't turn up on normal homework, but also not terribly complicated, the kind of thing you can figure out with a short burst of concentration.
So I went to math contests around Europe with other schools. The thing was that most kids I met there were totally ordinary at maths. Sure, some were really quite good, but most of the bottom 75% were indistinguishable from your normal kid who doesn't know at 15 what an integral is. The friends on my team weren't even in the top set math class at my little school, but my observation was that most kids from the other schools weren't either. Most were along for the ride, much like myself at school sports events where you also got a trip across Europe for participating.
I did okay at it, and in my final year we had a couple of really good kids on the team and won the contest. I thought that was pretty cool, but I also knew I wasn't close to the pinnacle of math contestery. Fact was I was like that kid who just had some natural ability but I didn't really practice a huge amount and nobody suggested there was a way to get much better. If you added up all the extra practice compared to just sitting in math class, maybe it was a couple of extra lessons a week, with more interesting homework. My math teacher was a great motivator whom I still keep in touch with, but we only had him and his experience.
Fast forward to now and I recently discovered a friend of mine got a top 10 at the IMO. Basically top 10 among all high school kids on the planet. I can ask him the occasional interesting question that I see on FB, and he'll know how to do it. He did proper years of training in math, had a very famous coach among others, and went through the eye of the needle several times. There's a world of difference between that and your casual have-a-go person.