Paywalled but would be interesting to see data on the percentage of SKUs these store brands displace.
Anecdotally have seen local regional chain systematically replacing a large number of SKUs within a product category with their own brands - Ex. 25 bacon SKUs across 10-15 brands down to 10-15 SKUs and only 2-3 brands aside from their own.
Same thing across Cheese, Milk, Salsa, Pasta Sauce, Salad Greens and many other categories.
Playbook seems to be establish large store and create local monopoly / oligopoly then aggressively copy anything that sells well and remove the competition from the shelves to create a local monopoly category by category.
Own brands are cheaper but much lower quality. As a shopper you have no choice - it's either the house brand or nothing now in a really high number of categories.