A city is by definition big (in terms of density) compared to the surrounding area. And yet, paradoxically, cities are better at supporting smallness than suburban and rural areas.
A small employer in the city doesn't need to offer a parking lot, because the city has ample transportation. It doesn't need to offer onsite meals, haircuts, or help with taxes. It can focus.
Further away from the city the big one stop shopping experience is king. First came malls, and then walmart.
This notion of big enabling small can also be seen with aggregators like Google & Facebook which enable individual niche publishers in a way that newspapers never did. But, unlike a city, the leaders at Google & Facebook aren't voted in by the people.