It is an undeniable fact that the last 1000 years of its history has not been great for the Indian civilization. We have seen the steady erosion of Indian cultural influence across Central Asia, East Asia and South East Asia. Within the subcontinent itself, the native Sanskritic high culture was replaced over the vast majority of its expanse by a Persian high culture imported from Central Asia & Iran. And this has never really been reversed up until now. When the Persian high culture was swept away, the Sanskritic or Hindu high culture did not come in its wake but what we had instead was the imposition of another foreign high culture, that of the English.
That we have had such a mighty fall is often not emphasised or even brushed aside by some intellectually dishonest historians. They even try to disingenuously argue that the destruction and plunder, often of great Indian temple cities, by Mahmud of Ghazni, was just par for the course in Indian history since apparently Hindu kings also invaded the kingdoms of other neighbouring Hindu kings and took away the idols of their presiding deities from their main temples.
But what the invasions of Mahmud Ghazni did to India is rather glowingly mentioned by the scholar Al-Biruni himself,
Yet read as per this post on Encyclopedia Brittanica,
Maแธฅmลซdโs conquest of northern India furthered the exchange of trade and ideas between the Indian subcontinent and the Muslim world.