In the Netherlands it's not a matter of population -- shops are not allowed to be open outside the regulated hours. I believe the law was introduced a few decades ago in order to protect the mom and pop stores (a misguided attempt to put mom and pop stores on equal footing with larger businesses. If the mom and pop store can't afford to stay open at night then nobody is allowed to. Because that's "fair".)

Since gas stations have permission to stay open around the clock they're used to get emergency food. You can also get food delivered on Sundays and in the middle of the night, so it's not so bad.

But in rural Alabama, at least, Walmart is open 24 hours a day, and chain pharmacies like CVS and Walgreens as well.

This is how it is in small New England towns also. I used to live in a lively tourist trap seaside city where everything closed after 9:30pm.