Big companies need stock.
Big rent and rates, staff bills, high utilities, debt to service, massive advert costs.
Can't service all that with no stock. It's why, IMO, many of these places pop up, trade for a few years and go pop because the business model is like walking a tightrope.
Never understood the appeal of a massive forecourt/supermarket with no margins personally, I just see it as a vanity thing. Much rather have half the stock with twice the carefully bought margin in it.