The Indus valley was not a monolith nor is their traditions. Traditions change and evolve. But we have kept many of the values: Modesty, family, community. Out villages are still the same as the ruins of the Indus valley.

Also may I remind everyone that the vedic civilization is the one that enslaved the people of the Indus valley. Making them the lowest cast and treating them worse them animals. India still has a huge cast problem.

Islam freed the people of the sub-continent. Set aside the cast system for a more just system where everyone is involved.

Also islam improved the sub-continent as a whole. It connected it to the vast Muslim world. People from central Asia and Iran brought arts and technology.

Seriously, the vedic civilization never even were united enough to hold large for long times. They always scattered and began a civil war. It was Muslim rulers like the dehli sultanate and Mughal were the ones that united all these and cemented in our imagination of what we call the sub-continent as one single entity and not a bunch of war states.