If someone does your job better than you and/or for less money, they will take your job.
A company that constantly threatens outsourcing is bluffing. If they have someone better, you'd be gone already.
When I work for those kinds of companies, I have no worries about getting outsourced, because I'm already looking for other work.
This idea of "be thankful you even have a job" is something that is drilled into workers to keep them from fighting back. The realty is in most cases, anyone can quit or be fired with short notice (2 weeks here in the US, not sure what it is elsewhere).