Why did Arab powers regain much of the Indian Ocean trade from Portugal after 1698?

After 1698, Arab powers, specifically the Omani and Mazrui Arabs, successfully reclaimed much of the Indian Ocean trade from Portugal primarily due to the strategic collapse of Portuguese strongholds in the region.12

The turning point was the fall of Fort Jesus in Mombasa to the imam of Oman in December 1698. This victory effectively dismantled the key foothold that had allowed the Portuguese to dominate the commercial systems of the western Indian Ocean. Following this defeat, the Portuguese were forced to retreat southward, while Omani and Mazrui forces expanded their influence throughout the 18th and 19th centuries, reclaiming control over coastal trade routes. This shift in power was further compounded by the rise of other European competitors, such as the British and the French, who increasingly challenged Portuguese interests in the region.312