I'm from the oldest metro city in India, and use the following:
1. Swiggy Instamart: Minimum free delivery threshold is ₹199. And flat ₹7 platform fees regardless of order amount. Prices are very high, offers are less, and product offerings are even lesser. I use it mostly to buy milk, but not regularly.
2. Amazon Fresh: Minimum free delivery threshold is ₹249, and no platform fees. Prices are high even after 5% cashback with Amazon Pay ICICI Bank Credit Card, and product offerings are less. I use it rarely lately.
3. Flipkart Grocery: Minimum free delivery threshold is ₹299, and no platform fees. Prices are really cheaper compared to other platforms, but product offerings are less. Also, they don't sell fruits, vegetables, and dairy products anymore. Just hate the fact their available delivery schedules far from order date. Been using it regularly now.
4. Blinkit: Minimum free delivery threshold is ₹299 and platform fees of flat ₹4. Don't use it much, as their product offerings are less and prices are generally high with less offers. Used to be their regular customer when they used to be called Grofers and weren't acquired by Zomato.
Apart from these, I really like BigBasket though, including its BBNow, since I have the Tata Neu Infinity HDFC Bank credit card. Sometimes over ₹2500 purchases, you get around ₹500-700 off after applying cashback and instant discount offers, which is really nice. Their product offerings are quite vast, and UX is amazing too. But just hate the fact they have less delivery schedules per day, and generally next day schedule is available, and also hate that if you buy vegetables from them, even if there's a 5g increase, they add a debit to your BB Wallet, and so the next time you shop, that amount is added to your total order value.