I shop at Family Dollar sometimes, and also Dollar General and (shock, horror) even Dollar Tree.
I shop at these places because I am very cheap, and these places are also often (not always, but often) very cheap and the selection is usually pretty good, for the size.
And before someone else blames math for my perception: I can math. I can also remember prices between the shelf and/or the website and the register, and between different stores. (I've been cheap for a very long time. One cannot succeed at being cheap without honing these kinds of skills.)
The shelves at these places aren't beautifully-faced. The lighting is shit -- lowest-bidder, lacking design coherence, and either too bright or too dim. The music, if it exists, is usually a Bluetooth speaker playing from an employee's phone or a single pair of thrift store speakers from a 1990s Aiwa mini system [sometimes, even fancy-style with one on each side of the building] with some local radio station or other playing. There's usually large delivery carts sitting around in the already-narrow aisles with fresh inventory that the 1 or 2 employees who might be present sometimes get time to stock a bit of.
And that's... that's all just fine.
I don't want to pay for beautifully-faced shelves, good lighting, and a professionally-installed overhead PA system that plays professionally-programmed musical selections in a professional manner. I don't want to pay for shelves that are magically stocked in the wee hours of the morning by a dedicated team of professional stockpeople.
Like, seriously: I'm not that proud. My goal is to save money; shopping for inexpensive canned beans and a gallon of milk from some factory farm does not have to be an enriching, transcendent experience.
So when I have need to buy stuff, and there's a Family Dollar across the street from the office and Dollar General is around the corner from my house? I cheerfully stop in and give them my money.
The employees are almost unilaterally very polite and helpful. They know the entire store's products very well, even if the price tags aren't always up-to-date. It's a good, quick, cheap place to shop for good cheap stuff.
(I see comments here that read like "I only shop at Whole Foods. I went to an Aldi once and turned right around and walked out" and all I can think of are callously demeaning phrases like "You blithering, sheltered, classist snob. It may be possible for a person to bring even less relevancy to this discussion, but I cannot presently imagine how that would be possible."
But I usually try to keep that kind of phrasing to myself.)