Outsourcing is about reducing costs. It's not good or evil. But it depersonalizes decisions on which service to choose and narrows the decision making criteria down to cost. Costs for service jobs are driven by people. So, when a company is choosing their janitorial service and they choose the lowest cost service, that means the service that pays the lowest wages or that cuts the most corners will typically win the contact.
Depersonalizing the buying decision and commoditizing human labor aren't good or evil by themselves. But, turning people's welfare into a math problem certainly leaves us open to making decisions we wouldn't have made if we saw the consequences through a human lense instead of only an economic lense. At best, it causes suboptimal outcomes for an individual while maximizing the aggregate benefit.
We can fight against it all we want, but everytime we buy a t-shirt, an apple, or an iPhone, there's a supply chain behind it built on the lowest cost provider. We are all part of that process. I hope I'm not evil for buying a cheap t-shirt. But I know I enabled some shady behavior that made it $1 cheaper.