xavi as a coach is not too mature, he still needs more experience to be called a coach who has successfully built barcelona, the pressure that xavi faces is also quite large because if he is not able to bring barcelona to win the UCL trophy then people will question credibility it's training barcelona, in a few hours barcelona will face a friendly match with arsenal, let's see what barcelona can do against arsenal.
Looking at the list of his coaching history you are right he is not a mature enough coach because his coaching history is still very minimal, but it's great with minimal experience, and at the beginning of his training at Barcelona he managed to bring his former club when he was a player to become a laliga champion, maybe there will be many who say it happened because their rivals were not in a very good condition but that's not entirely true because it's proven that Real Madrid managed to beat Barcelona in the Copa del Rey final and Real Madrid made it to the semi-finals of the UCL, so Xavi actually faced a difficult season at the start of his presence at Barcelona but with a squad that there is something that is not much different from the squad when Barcelona under the old coaching managed to maximize every opportunity that existed.
As for the UCL, it is quite difficult to predict whether Barcelona will be able to return to playing well like when their star players were still there, but of course, Xavi will try to bring his team to play well, but I predict that the financial difficulties that Barca are currently experiencing will become an obstacle for them to be able to excel in Europe because of the difficulty in buying players because currently their new players are dominated by players from free transfers.