>Those who order grocery delivery online would benefit from price comparisons, because they can order from multiple stores at the same time.
Not really, since the delivery fees/tips that you have to pay would eat up all the savings, unless maybe if you're buying for a family of 5 or something.
Instacart, Uber Eats, DoorDash all sell gift cards of $100 for $80 basically year round — when you combine that 20% with other promotions I often have deliveries that are cheaper than shopping in person.
Uber Eats and Deliveroo all have list prices that are 15-20+% above the shelf price in the same supermarket. Plus a delivery fee, plus the "service charge", I've _never_ found it to be competitive let alone cheaper.
