Please don't pretend your universities taught rocket science. They were Buddhist learning centers - as useless to modern world as kindergarten books (actually kindergarten books are a bit more useful for the little ones).
Anyways, Nalanda was set on fire by some angry Tirthikas - not Muslims. Do some research beyond internet forum/blogs hearsay. Ask your own historians.
Lol you had nothing. Muslims gave you real roads, like the
Grand Trunk Road - connecting Chittagong to Kabul. Quite ambitious; read about it.
Economy? Which industry?
All you had were fertile land - Muslims introduced more sophisticated concepts - like currency (
Rupiyah).
Want to go back to the days of
Sati practice?
If you could turn the clock a 1000 year back, visit the era before Muslims arrived and seen the brutal oppression common Indians endured at the hands of the 1% real unmixed, upper caste - I'm sure you wouldn't be so proud of your religion today!