Why is a real fulfilment centre better? I can see an Amazon centre with robots etc being more efficient, but other warehouses seem no more efficient than going through shelves at a walmart.
I would think there might be lots of reasons, but one that comes to mind is that supermarkets are physically designed to get the customer to spend as much time and money as possible in the store as opposed to finding the items on their list(s) as efficiently as possible like a grocery delivery service would want its workers to be able to do.
Amazon just recently started to use robots. Most existing operations still use physical labour. FCs are more efficient, as single entities, because they are designed as such. They have proper infrastructure, tools, people, processes.
For grocery fulfillment, I don't think they are better at scale. Because they are for from the customers, they are not everywhere. Existing stores, so, are there. They use established replenishment from existing warehouses. Which means you have to use existing staff and store processes (and software) to fulfill orders. Which is hard. So it's either expensive or hard to do (which could expensive in itself). Over simplified.
Supermarket floors aren't designed for pick and pack efficiency, they're designed from the ground up for phycological manipulation.
Warehouse trumps Supermarket for efficiency by multiple factors easy.
Just as an example imagine the 50 most ordered items. I can put these in a tiny area closest to my packers in a warehouse. How far to you think you'd need to push a cart between those 50 points in an average Walmart?
A good fulfillment system tracks its inventory and communicates with the ordering system, so you can't order items they can't deliver. That's the big problem with ordering online from grocery stores - about 80% of what you order shows up, which is a headache for both buyer and seller.
Mostly because markets deliver a less consistent experience (delays, cancellations due to vacations), and you face situations where your employees and customers are fighting over the last bag of chips. It also becomes harder to plan logistics because most stores (at least where I live) have limited real estate.
The semi-automated ones have different issues. Only Amazon really has the tech fully figured out to a degree where issues are resolved almost instantly. Amazon can also use less but larger scale fulfillment centers because they deliver mostly small objects at an arbitrary time, whereas you can't leave 6 bags of groceries at a front door.
