Plus, Flipkart likely has a lot of expertise in mobile as well, given how much of India's internet usage is now mobile-only.
I reckon that expertise is worth a lot for any company looking to expand in the developing world
I don't think this is true.
You have to enter a pin code when you order from Flipkart. It's used to compute the delivery fee.
Flipkart also used to refuse to deliver products to some pincodes though the list of supported numbers has definitely expanded over the years.
In short, I don't know what their coverage level is, but it boils down to: you can't get a package delivered to anywhere where there is no post office.
It's fine for India, but I don't think a lot of the business models and know-how that works in India transfers easily to conditions in the U.S.
KFC/pizza hut/dominoes don't set up shop in remote places 'without infrastructure'. It doesn't make "business sense".
They are mostly limited to cities. They don't deliver long distances, food delivery in general is limited to 2km, and they certainly don't deliver without a name, contact number and delivery address.
'They' here means the transportation, not the marketplace. It comes down to the transportation to make sense of improper addresses and provide wide coverage.
Also, Ekart has a very limited serviceability and flipkart has to rely on third party logistics.