Yes we have written about 8621 in our blogs, we help in the documentation that individuals require to be compliant for FBAR and PFIC.

Post the zero interest rate regime, it's unlikely US will give that much return as it has in the last decade. AT the same time, India is in a better position vs last decade because foreign reserves are stronger, so depreciation probability is lower as well as fundamentals are better - RBI revised its growth forecasts upwards from 6% to 6.8%, capex to GDP has doubled in the last 7 years etc.

Overall, these factors make India a good diversification for X% of your capital, X can be higher if you choose to move to India, and lower if not, but it can be non-zero, provided the friction of investing is removed