Sicario2 Forget age. If he’s young enough to get praised he’s young enough to get scrutinised.
He is our best player and talisman regardless of being 22 therefore the standards/expectations are raised.
Cesc at the same was captain of the club and already world class.
What did Cesc win by that age that Saka hasn't to make him world class? Both had an FA Cup, though I'd argue Saka had a much bigger impact throughout the run to winning in 2020 than Cesc did in that 2005 win.
Both lost a European cup final, both contributed hugely to a title race we ended up losing each time by 4 points with almost the exact same total.
Cesc might have won Euro 2008 by 22 but he was a sub for the majority of the tournament as well as in the WC2010. Saka meanwhile was a starter for England at the WC.
Both are our first choice penalty and corner kick taker and both score and assist a lot of goals, both are the talismen of the team and our most valuable player.
I'd say on all the requirements you've set out, both in terms of achievements and the importance they have towards the result of the team at the same age, they're both WC players.