Innovation is required, when a problem is being solved.
The so called
_"delivery of food via a mobile app to someone who has the means to afford it_", is not at all a problem.
It has been solved at least 10 years back, when mobile phones became ubiquitous.
In a metro, even a chinese-food kiosk guy delivers to nearby areas. One just has to call.
Probably scenario is same in all the cities where in these food delivery companies are operational.
When the problem does not exist, how much innovation and differentiation can be done?
And that is why food delivery companies are not successful (earning money),because there is no problem there in the first place.
People buy from these food delivery companies because discounts are there, and they will buy only till discounts are there.
Investors fund because market is big, just like e-commerce, and no one has succeeded in this space yet.
But no one has not yet succeeded because, there is no problem !
"Delivery of food to those who have means to afford it", is a solved problem ages ago. Just re-inventing the wheel with the use of a mobile application, does not means that, the problem has re-emerged or had been dormant, waiting to be solved.