Is it permissible to boycott a friend who displays bad manners and engages in futile arguments, especially if the boycott leads to an improvement in one's religious commitment?

The basic principle is the prohibition of estrangement between Muslims for more than three nights, as evidenced by the Hadith: "It is not lawful for a Muslim to shun his brother for more than three nights." However, if a Muslim observes in his brother what contravenes the ethics of Islam, he should advise him and remind him of Allah. If he persists in his behavior, then it is permissible to distance oneself from him, especially if associating with him brings about a deficiency in one's religion or harm. Ibn 'Abd al-Barr mentioned that a beautiful estrangement is better than harmful association. One must be careful not to make the estrangement complete; rather, it is sufficient to greet him upon meeting and similar interactions.