Design, the gap is nonexistent in terms of talent deployed (though we have some way to go to have homegrown product companies). Which puts us roughly where Europe is.
Also consider, a tiny percentage of the Indian population is a ridiculous number of people. Dwarfing pretty much any other country except China.
Your last point on welfare and corruption is also false; 35% of government spend is on interest payments (which is kind of normal for most countries?) and 30% is on infrastructure and other capex. Defence is 8% and central welfare schemes plus co-sponsored schemes with the states are only 26%. The point being, while corruption is definitely a problem, it doesn’t significantly come out of the central budget. And welfare is smaller than infrastructure spending even if it’s quite significant (and it better be, in a country like this).