Economies of scale are when a firm gains an advantage by increasing production and lowering costs to spread over a large number of goods. So in terms, yes this has direct relevance to companies such as Walmart.

Economies of scale is the key to Walmarts all-around success. They have a very large network of others such as Sams Club and other Walmarts such as the neighborhood market. They have a large variety of products that allows them to sell for a cheaper price than most competitors in the same market as them. The store Sams club is a membership-driven store where you buy everything in bulk options making the items per unit price cheaper than buying one single item of it. But not only does that store tend to lean on that option Walmart is able to keep the prices low because they also buy in bulk and evenly distribute it out to the stores to sell.

When you have the options that Walmart has you make yourself a viable shopping option for everyone. Many people consider it a one-stop shop which most like since they only have to go to one store. When you talk economies of scale Walmart is one that will always be included in that conversation regardless.