Does that prove Xavi would have performed great at NT level or in Champions League when he was 23-24? No it does not. The absence of games from Xavi at the highest level (Champions Leagues and Euro) at that age is a proven fact and can't be denied. Xavi was unproven at the highest level at that time, so he was not world class. Maybe he had the potential to be world class even since a young age, in a different context. That's different from actually being world class.
Xavi was born in January 1980.
Season 1999/2000, in April/May, he was aged 20 years and 3-4 Months.
CL semifinal 2nd leg, Barcelona:Valencia 2:1:
https://www.theguardian.com/football/2000/may/10/championsleague.sport1
Season 2001/02, in April/May, he was aged 22 years and 3-4 Months.
CL semifinal 2nd leg, Real:Barcelona 1:1:
http://www.uefa.com/uefachampionsleague/season=2001/matches/round=1548/match=1024728/postmatch/lineups/index.html
We were knocked out both times in semis.
Imagine that we won a CL in one of those years... Xavi would be hailed as the best CM in the world and a brain of our team.
Tiny things and some luck can totally change things.
Further, look at our team in 2002, our midfield: Cocu (hardworking but not creative CM, like Rakitic), Fabio Rochemback (totally crazy guy, with 10 brainfarts per match and shooting at goal in every single opportunity whenever he receives the ball), Luis Enrique (crazy all rounder, but mostly a fighter and not a creator) and Xavi.
In attack, poor Saviola and Kluivert.
Imagine if we had won it that year. Our winning team would have been: 10 runners without too much creative abilities, and only Xavi as the only guy who can create something and connect our lines.
Imo, once again, it is extremely HARD to compare Barca's history with younger fans, who lived mostly in Pep's and post years (or post 2006).
We can read 1000s times here things like:
1. we are Barca, we don't fire coaches easily.
False. That happened only during our glory era from 2006 till today.
2. we are Barca, we rely on La Masia.
False. It happened only in the last 10-15 years when we were lucky with once in a ligetime generation.
3. we are Barca, we keep players in our team for 10 years.
False. It happened only in the last 10-15 years when everything was perfect, when we won 100s of trophies and when there was no need to fire coaches, buy new players, tweak systems etc.
To some extent, the same is with Xavi and with our teams from 80s, 90s and similar.
In early 2000s, Xavi played without Messi, without Iniesta, without Busi.
He played with donkeys in midfield and with donkeys in attack.
The same as when Pep comes to Man City and he can't teach those donkeys to play a perfect Tiki-Taka.
I mean, Xavi's midfield partner in 2002 was Fabio Rochemback:
If you think: wow, this guy on a pic looks stupid.
Well, more or less, that is exactly how he played.
So, to some extent, I could ask: whether Xavi improved THAT much during Pep and Rijkaard, or he wasn't playing with donkeys anymore but with Iniesta, Deco, Ronaldinho, Messi, Busquets etc.
Also, once again, Xavi aged 22 had 2 CL semifinals on his back.
That's better than current Verratti, aged 24.
This forum considers Verratti as the best Barca's fit and probably as a top3 or top5 Cm in the world.
Verratti doesn't have any NT success or any CL success (since his team is not good enough for a CL level).
Is Verratti a world class then?
Imo, majority of people here agree that Verratti is a pure gold.
Once again, imo, young Xavi was the same as current Verratti. A world class player, surrounded either with donkeys in his team or with a team who is not good enough to raise Xavi/Verratti to even higher level.