Whether you like it or not a midfielder is only ever as good as his forwards. Our forwards are the weakest part of the team. So naturally when we run 4 mids nobody is going to score and so people like Gavi and even gundogan 99% of the time look like 0 output players. Gundogan made exactly 0 good plays before the assist for Pedri.
Pedri is the teams best player. He is an actual Elite difference maker. FDJ can be made to look good because his literal only role is move the ball up. Which is good and all but he isn't tasked with being the cutting edge like Pedri/Gavi/Gundogan. FDJ is a very good player but I'm simply saying he didn't cut it playing further up the field either in the first place.
Also let's remember players improve at different rates. Xavi and Iniesta weren't as highly rated at these ages. Because back then they were broken in correctly unlike now where we start guys at 16/17 and they learn some bad habits that have to be unlearned to improve upon. (Think Gavi yellow cards and diving)