what is one common cause for the decline of the Islamic Gunpowder Empires: Ottomans, Safavids, and Mughals

Invasion, economic destitution, and growing European power

Explanation:

its main object was the establishment of "settlement houses" in poor urban areas, in which volunteer middle-class "settlement workers" would live, hoping to share knowledge and culture with, and alleviate the poverty of, their low-income neighbors.