Hiring only local triggers what's known as the "church problem" in business. Hiring someone from your church statistically provides the worst work. Psychologists say that this is because of two reasons. The first is just math, you eliminate 99.9999% of the world and try to pull an expert from a tiny pool. The second is that you prioritize locality or membership in a small group over skill, reputation, or ability to do the work. That alone is bad enough, bit picking someone for that reason also tells them that their value to you is because of who they are, what they are a member of, or where they live - which is another way of telling them that doing a good job at a good price isn't important to do. When you make someone believe that their value is already provided simply because of who they are, there is literally no incentive to do a good job and, in fact, a pretty heavy suggestion that they can overcharge and under-deliver and it won't be a problem because they've provided their value already simply in being whoever they are.