I disagree. Xavi is not the best coach ever. He is a pretty weak guy who got lucky that Barcelona is more or less part of his name. As a player, he was an amazing midfielder, but I never saw him as someone who is a good coach. I see how a lot of people are celebrating him, but please compare him to Gurdiola. No way would he ever be able to be mentioned in one breath with Guardiola. Xavi is the worst case, but sadly they need him.
It's true, currently Xavi doesn't deserve to be called the best coach ever. However, it is possible that in the future Xavi will become a very great and accomplished coach. The reason is, currently Xavi is still relatively young as a football coach.
So it is natural that currently Xavi is still not good and has many shortcomings in coaching his club (Barcelona). Because as far as I know, Xavi started his career as a coach in 2019. So up to now, that means Xavi has only been a football coach for 5 years. So having been a football coach for approximately 5 years, Xavi certainly doesn't have much experience. Moreover, with experience coaching European clubs, Xavi certainly doesn't have much experience. The reason is, during his career as a football coach, Barcelona was the first club he coached. Because previously Xavi was a coach at a club from Qatar (Al Sadd). But even though Xavi's experience as a coach is still limited, I think Xavi can be said to be a pretty good coach. The reason is, last season Xavi successfully brought Barcelona to become Laliga champions.
And if you compare Xavi with Guardiola, it is clear that Guardiola is superior. The reason is, Guardiola already has a wealth of experience in the world of football coaching. So I think comparing Xavi with Guardiola is not appropriate. The reason is that Xavi is a new coach, while Guardiola is an old coach who already has a lot of experience.