People often romanticize the "mom & pop" places, but there's a reason that most consumer-facing companies are very large, and those reasons were enumerated by the OP.
Also, there's a good deal of selection bias going on. If you had a successful business, why wouldn't you look to expand it to multiple locations? Running a single store makes your business vulnerable and usually requires a lot of time.
I’m not sure I agree with the diversity argument. That argument is based on the biological principle of natural selection. However, an economy isn’t a biological system: its a man-made system that is designed and run by an intelligence, actually many intelligent agents working together.
Biology is not designed or run by any intelligent agent that we know of. When people apply the diversity argument to non-biological systems, it makes me think they are actually and really arguing for intelligent design of biology.
My argument is a nature centric one, indifferent of biology. Biology is nature through carbon based life forms.
My argument still holds, if you over centralize or lack diversity (not in the social science race or sex based sense) then you’ll run into issues. Examples include Russian central governance, as opposed to more independent localized governance and sustainability. Another is non diverse economic production, for example many middle eastern countries.
People often romanticize the "mom & pop" places, but there's a reason that most consumer-facing companies are very large, and those reasons were enumerated by the OP.
Also, there's a good deal of selection bias going on. If you had a successful business, why wouldn't you look to expand it to multiple locations? Running a single store makes your business vulnerable and usually requires a lot of time.