Missing out on that rent doesn't change the landlord's lives in any way in many cases. They're willing to just sit on the vacant.
Some cities handle this by charging landlords a fee for having vacant storefronts. Some people think this is mean to landlords! But really, it's just changing the landlords' calculus. 🤷🏿♂️
Those cities want fewer vacant storefronts, so they make it more profitable to have a lower paying tenant than a vacant.