Swiggy and their discounts. How?

I have a genuine question. I am a frequent user of Swiggy Instamart, as I’m sure half of us here are. I’m always baffled by the crazy amounts of discounts swiggy levies on the MRP. I’ve bought basic household groceries at a discount of 50% and more. Not through a coupon code, just slashed prices. With swiggy going profitable, how do they manage to do so?

Do they buy products in bulk from a cheap source? Why does my neighborhood shopkeeer not know about this? I have so many questions!