Information is critical for driving free markets. Instacart is pulling some sleazy shenanigans, sending them down a path pretty similar to where Uber has ended up. I don't make it a habit of patronizing businesses that use deceptive pricing practices to try to rip me off.
Now it could be something consumers DEMAND which would give a competitor an advantage if they did it (see Everlane with their transparent pricing) but it's not unethical or sleazy not to disclose the underlying costs of your goods.
Instacart shows you the final price. The price they paid for the goods is immaterial - you're choosing the convenience of not having to write your own delivery app, recruiting employees, or set up payment.
When you walk into a book store, do you demand to see the book price broken down into manufacturer's price, store rent, employee pay, and store profit and complain when the difference between the manufacturer's price and the retail price is too high?
It's the same reason I think mechanics are shitty when they charge 50%+ markup on parts for auto repair. I'm paying you for the service - the right thing to do is to show the cost of the service separate from the market price of the product.
Alcohol/food at a restaurant is different - it is clear and known that service and product are interwoven in the list price.
They're not intentionally obfuscating anything. You know how much your bill will be before you order. What it costs them is immaterial.
Would you expect a clothing store to tell you what their individual per-unit cost is for clothes you're buying, and to tell you how much money they're charging you for opening a storefront and negotiating with the manufacturer?
What's $80 worth of groceries? It's what you're willing to pay $80 for. The grocery store is marking up the food from their suppliers, is that a rip off? Grocery stores in urban areas charge more than in rural areas, rip off? When there's only 1 small store in an area (food deserts) they charge 10-30% more - an outrage?
This is great information to have and a benefit to consumers that they know the difference, but if Instacart gives you a price and you pay it then that's a fair price by definition. It's not an outrage in any way.