Swiggy business plan|ideas for business

The business plan of swiggy be.....

Swiggy give 30-40% discounts on orders but how ?
It increases prices of food by 15-20% . And as mentioned above taking commission from restaurants upto 15-25% for increasing their order delivery.
As in restaurants business profits margin is approx. 50% , so restaurants happily give 20% commission .
They also give their delivery boys higher than other food servicers, so it will increases user experiences .
It means their is no cash burns/use for giving discounts of investors.
They uses this cash for their application maintenance , research expenses etc.

But the question arises why investors invest in swiggy ?