Testing will always be part of software development, so yes it should have a good future for this kind of job.
From my experience in system implementation, especially in a big project, with a big amount of resources, there’s always have a testing team consist of multiple roles and positions to handle all the system testing. And yes it should be better if the tester know the basic for each particular module they tested, at least from end user point of view.
Regards,
Edward