Is it permissible to boycott a sister who refuses to leave her husband, who does not pray, drinks alcohol, uses and sells drugs, and does not provide for the household, even though she is aware of the impermissibility of staying with him, and despite continuous attempts to advise him?

This man has committed major sins, including abandoning prayer, which the majority of scholars believe does not lead one outside the fold of Islam. Therefore, his wife is not required to separate from him. She should advise him with wisdom, explaining the gravity of his actions, and seek help through prayer. If he repents, that is excellent. But if he persists in his error, it is then preferable for her to seek a divorce.