10's are obsolete. Look at DeBruyne and Silva they're both 10's who converted to 8's or more so hybrids. Look at Mata he's a shadow of the player he was at Chelsea(funny enough he admitted that 10's are obsolete) Same goes for the Liverpool team, they don't play with 10. That's why Özil is struggling, because he can't adapt and find a new chamber to his game like the likes of DeBruyne. shyt is evolving. Dude hasn't been the answer for a long time. Creators are required to do more than create. Özil is gonna come back in the team and do nothing.
The positive is that there are so many young prospects around the world.
You're forgetting that both Silva and KDB also played on the wings before joining Citeh and while there, mainly in pre Pep days, where Citeh were more 442/4231.
Milner, Henderson, Wijnaldum, Fabinho also started out on the flanks before coming inside centrally.
Ozil stopped improving once he left Real/won the WC.
Mata's lack of speed/athleticism caught him out. Also majority of his career he was played out wide than inside.
Languid, non athletic/explosive #10 are obsolete. But #10 can still work, just have to go old school and having them as the SS and not the AM. Most of the Inside/Wing forwards of this era are really SS anyway.
And if we keeping it all the way reality, the 2 players known for being the best #10's of the 21st Century, both played out wide and came inside. And one of players was seen you much of a liability to play centrally.