Bangor is isolated. With sparsely populated areas on all sides, people in that area do rely on Bangor for basic needs but these are poor rural towns. People who don't like the bustle of Portland like to use Bangor as a second option. It's much cheaper to live up that way BUT it comes at the cost of lack of resources: southern Maine has the best Healthcare* and more options available for just about anything. Bangor does not have the same amount of money coming into it with rural towns on all sides and it also does not have the attractiveness of the ocean at its doorstep.

*I worked at MMC for about 5 years and briefly worked at an orthopedic office in Ptown. There were people who drove from as far as Caribou and Presque Isle to see Portland area specialists because nothing closer could help them.