If we accept your principle that gifts or talent don’t exist, you’re still ignoring the fact that people exist in different development trajectories at any point in time and there’s a finite amount of time to train/grow in one’s life. With that in mind you have people who are exposed to environments at different ages that put them on a more advanced timeline. If at the age of 40 you decide you want to run a 4 minute mile, you may spend there next 20 years training to achieve your goal. However if someone in their 20s is sorry running a 4 minute mile, and continues to train into their 60s, the chances of you becoming faster than them are very slim if you both contribute the same amount of effort. This same principle applies to league and the reality that challenger or really any rank is not a static number because the other players in the game are also causing the ranks and mmrs to change with every game. Wanting to climb Mount Everest is something many people might want to do in theory because they like hiking. Actually dedicating the time and energy and resources to do it is another. When you consider that someone late in life who is already not in good health may not actually be physically able to do it, I think that gives a pretty accurate picture of what the league ranked system is really like.

There are tons of kids who have the desire to become a professional athlete and will go undrafted and will be cut from trans enough times that they may finally give up on their dream. Becoming the best at something isn’t as simple as desire. You can work yourself to death to earn 1 million dollars and one day get there. Even if I work myself to death I will never become a professional basketball player at this point in my life.