Depending on the store, there may be additional costs in terms of usage and shipping costs. You can't select each item by hand. Buying fresh produce can be a challenge, as you can't see the quality of the item before you buy it. You may still have to go to the grocery store.
Except for some Amazon Fresh orders, stores and third-party delivery services send their staff to local grocery stores to examine the aisles, select the items you order and then take them to you, which is not an efficient operation. While these workers may move faster than you (it helps that they work from a limited, organized list and don't bring children with them to the herd), those additional labor costs translate into higher bills for you. However, for most shoppers, grocery deliveries are aimed at saving time, not money. Many people still prefer to do their own shopping.
In addition, certain items may be more expensive through Instacart than in the store. This is common practice for grocery delivery services that partner with multiple stores. With most shipping options, you can sign up for an annual membership and get unlimited free delivery or pay reduced shipping rates. Instacart is a grocery delivery service that employs personal shoppers to shop for you and then deliver the food to your home.
The grocery delivery service offers several benefits, the main one being the convenience of having your groceries delivered directly to your door.