Any goal keeper would have saved that it wasnt even in the corner he just froze and made it look unstoppable
I'm not sure if "any" goalkeeper could save that nice shot, but a GK on the mainstream international level certainly would.
Simply look at RM, Atletico M., both have much better and more consistent goalkeepers. With Stegen Barca will always have a disadvantage against the main opponents, not to mention keepers like Buffon.
In Bravo's time the defense was not a lot better, still the mere consistency of Bravo's performance made it much easier this attach-oriented team to win more.
The mere reliability of the GK is a huge factor in this game, specially for the present Barca, having so many problems in every other part in the team, thus a good average GK would be a blessing for the team, even if Stegen is indeed capable of great saves, but only occasionally so.
He is bad with high balls, bad with coming out, generally bad in judging situations, his "freezes" are simply unacceptably ridiculous, although he has great reflexes and other qualities too.
But believe me, he is actually a weak link of the chain, because he is anything but reliable.
He has shown it against Roma, his own goal against USA in 2013, the goals he conceded from Atletico, Celta, Slovakia, etc.
https://www.youtube.com/watch?v=s7QLFs-yaTg
So all in all he does nightmarish things, besides good stuff, but NOT a reliable goalkeeper for sure. Good? Sure, Reliable? never...