LA county has to compete with Orange county, Ventura county, and San Bernardino county. To say that business and resident poaching exists would be putting it mildly.Los Angeles County isn't impacted negatively because businesses and residents don't have other options. There are no flat valleys adjacent to the Pacific ocean sitting undeveloped next to L.A. Minneapolis, relative to Los Angeles County, has very little to offer adjacent locales can not.
I disagree that Minneapolis has little to offer that adjacent locales cannot also provide. Minneapolis (the city, with St. Paul) is really the only urban place in MSP. The city has a wealth of amenities: natural, cultural, academic, financial, political, etc. Although the suburban counties have a few wealthy homeowners and some corporate campuses, they essentially have nothing to offer except cheap land. With deindustrialization, this isn't much of an incentive to a high value-added company. Except maybe for warehouses and tract subdivisions.