How hard is it to find a Messi-caliber player?

A common refrain/complaint of Chinese soccer fans is, “How come we have a population of 1.3 billion but can’t field a good starting eleven?”

Which had me wondering if, if China truly went all-out and spared utterly no expense in finding or cultivating talent, if it could eventually field a starting eleven for its national squad consisting of a Chinese equivalent of Messi, a Chinese equivalent of Neuer, a Chinese equivalent of Neymar, a Chinese equivalent of Ronaldo, and so forth. Or is it not as simple as “You’re guaranteed to find a 4-leaf clover if the clover field is big enough?”

Do all the potential players have adequate nutrition/health? Do they play the sport religiously from age 3? Are they surrounded by many other people that also play at or above their skill level so that they can improve? Do they have instructors that can teach them strategy and tactics along the way? Do those instructors have life long affiliation with the sport at a suitably high level for what they’re coaching?

Messi is pretty much a consensus all time top 3 player. He’s extremely rare among the hundreds of millions of people that play the sport under ideal conditions to become great. Even if you were to wish into place all the history, coaches, fitness, etc and train up every boy from birth, I wouldn’t expect a Messi right away.