The grocery store is not designed for the level of efficiency a system like this needs. It's designed to make you walk from one end of the store to the other slowly looking at all the products to gather each individual item on your list. It's great for marketing but terrible for efficiency and for social distancing. As long as the delivery and pickup is done from the same stock the grocery shoppers pick from it'll never be as reliable as just going in yourself.
Obviously, having someone go to a store just for your purchase and walk along all the isles to pick stuff up is horrendously inefficient.
It's obviously inefficient to send someone to a store to grab stuff, but "giant room with products on shelves" is a pretty efficient setup. They can do some of it in the back room, or a warehouse full of pallets, but to a large extent companies end up building "dark stores" that are almost the same as a normal store, but with no customers allowed in.
But the essential difference is the "push vs pull" - instead of one delivery pulling items from everywhere (which is a new process that grocery chains did not have) you have the supply process pushing items to many delivery targets, which is a process that grocery chains already have and have optimized.
Instacart had early advantage because full scale grocery delivery infrastructure was broadly in its infancy but if and when the likes of Amazon, Wal-Mart and others go full scale on their own offerings then structurally it would seem impossible for Instacart to compete with that.
Amazon Fresh might be a real competitor but it seems like they're running into the same problems as grocery stores.
I agree completely. I signed up to be a shopper with Instacart, and the experience was awful. To get work, there was a 'first come, first serve' queue I had to check at a specific time several times a week. Not great, I thought, but okay, we'll see how it goes.
Well, apparently people had set up bots or something, because all the orders worth taking were scooped up in less than a minute when the appointed time arrived. I couldn't even read the screen fast enough to see what was there before it was gone. I walked away in disgust immediately and never considered working with them again.