I like sports science as a hobby, in general, i don’t think children should specialize until they get competitive. I know a lot of top American college systems like to select recruits who play multiple sports, and then specialize once in college. For a child as young as 10, have them play multiple sports, track and field, tennis, wrestling, gymnastics and biking are sports you could have kids do that will complement their athletic performance. Football in Europe has the same advantage as weight lifting had in communist countries such as China, and Russia as they have so much talent and can afford to be super specific all the time with a high intensity, it doesn’t matter if 80% of people burn out, because you will still have hundreds of thousands of kids from the millions who can stay in the system, and from there you pick your top players.
They are different types of players.
Static 10s don’t fall into the vertical, pressing and positional style of play we see today. Guys like Felix and Havertz operate in the hole, with two wingers and a striker a head of the. In postional play, you want to open up the hole to have wingers, midfielders or a striker to come into to recive the ball, if there is a 10 in the hole permanently then there will be a 6 playing in the area occupying the space to break up play and press your 10. 10s don’t play well through a low block either. If you want to play around the block then you are better off with two 8s who can still deliver and assist but can also provide support defensively on the wings.
Two examples of this is Peps City and Klops Liverpool, who play with a 433, two 8s, two wingers who come inside and a forward that can drop deep (minus haaland)
There are 10s who are successful, Tomas Muller plays there, he has a high work rate and operates more as a shuttler moving around into channels than sitting to play passes. Bruno Fernandes is also an effective 10, he moves everywhere in the opponest half to play passes.
Joao Felix plays on the left now, but is still quite stationary, his movement in the atleti game was almost restricted to an 8th of the pitch (near left quarter of the opponents half)