It's no secret that online grocery shopping is a real thing, and many people are doing it. However, it has its drawbacks, mostly that the customer can only choose from items sold at one specific store, and often the online assortment is smaller than the assortment offered in the store.
Enter Instacart and Google. With services offered by these two companies, customers can now shop online from multiple stores and wait for one delivery that includes all of the items purchased. All of the sudden the traditional supermarket is serving as a distribution warehouse.
An article I read envisions a day when no one visits supermarkets anymore, but I think that's far fetched. Remember when analysts were saying that online sales would prevent people from visiting bricks and mortar retail stores? In a few short years we have learned that online channels and the in-store experience complement each other, and both mediums will most likely be around for quite some time.
So, I think people - including me - will still visit supermarkets. But there's plenty of room in the industry for online sales, and for whatever the Googles and Instacarts of the world think of next.