I am aware of the deficiencies, but also very aware of the progress being made. There is no magic wand to wave to make people not be like people and change a vast, diverse population into something they are not.
What is about "a vast, diverse population into something they are not"? Are you saying India can not be a middle-ish income country like China/Thailand/Malyasia etc. I would like to believe that wise choices by the electorate and good leaders and some luck can transform the country (or any country). Japan/South Korea/Thailand/Malaysia all did it. Some of those countries are vast, some diverse and some had less advantages than India.
If you believe in the opposite that then are you not giving into the ideas in the "Clash of Civilizations" or worse "Genetics as IQ" crowd?
India has a very vibrant local economy which does not show up in nominal GDP. By GDP by PPP, India is the third largest economy in the world (https://en.wikipedia.org/wiki/List_of_countries_by_GDP_(PPP)). I consider India to be a solid middle income country, not any less that other countries you are talking about.
I am actually fairly proud of the changes I see in India in the last 20 years. I Some of the key changes I have seen (by no means complete): 1. Improvement in road transport with a nationwide single toll provider. 2. Indian railways has always been there as an affordable means of transport. 3. Getting a passport is now a couple of days and less than 24 hours with tatkal. 4. Healthcare is free for all. Yes, it varies from state to state, but government hospitals are available for everyone. Even otherwise, it is affordable. 5. Air travel went from just for the rich to middle class. 6. Government and publicly funded schools are reasonably good (The project director for Chandrayaan 3 came from a government school).
And yes, I am also very aware of the issues - political class abuses the power to enrich themselves. Different states have different development indices. But perfection is not needed for improvements.
Thank you for the clarification
Using net migration as a statistic for the health of a country is no more (or less) valid than the TFR or longevity or anything else equally plausible.
Q: Say that Sundar Pichai or Vinod Khosla had not left India? Would their impact on India larger or smaller?
I would say India is better off that they left, maybe you differ?
It's always about culture.
The British Empire employed a strategy of divide-and-rule: it encouraged and amplified the caste system, and also encouraged the partitioning of society along religious lines. On top of that, it layered the English class system, and a horribly-botched partition.
I don't mean to imply that Indians don't have agency; they've had 80 years to fix the mess the Empire left them with, but things are getting worse (IMO).
I don't like empires. I look forward to the breakup of Great Britain. I think the USA is struggling to hold itself together. Most complaints about China are about the imperial domination of ethnically-distinct regions by the Han. The current war in Europe is a war of imperial conquest. I wonder whether India might be too big and diverse to manage, too?
80 years isn't a long time, and over many years I expect it will be sorted out.
/me not been to India for 40 years, opinions based mostly on mainstream news