Agree. Juventus doesn't need to replace Motta because Motta still showed reasonable results for Juventus. Motta just becomes the Juventus manager in July 2024, he needs a more time to improve Juventus team. The current squad may be not strong enough, Motta needs better players in the next transfer windows. So, Motta can make an ideal squad for Juventus in the next season. I think the current squad looks not quite competitive.
Of course, Xavi can get difficulty to handle Juventus because he never knows Italian domestic competitions. Xavi probably is not suitable with the current squad. So, changing Motta with Xavi may not solve the problem.
You are right Replacing Motta with Xavi might not solve Juventus problems. Motta has just started his job and it is not fair to expect him to fix everything right away. He needs more time to understand team find its weaknesses and make smart decisions about which players to sign in future. Current team might not be good enough but that can be fixed by choosing right players. Xavi on the other hand would have to learn a lot about Italian football and it is unclear if he could adapt fast enough. It might be better to stick with Motta and give him support and resources he needs.