That takes a part of your supply chain and puts it in control of somebody else. You might not know what's going on on a day-to-day basis, or week-to-week basis, and then you have to understand how they're handling risks at their factory.
You have to work at identifying and maintaining and keeping abreast of the risk because it's being done somewhere else. Whereas if you own your own manufacturing, you have much better control over your costs and products.