Many high school teachers and college foreign language instructors have been replaced by computerized language learning laboratories.
Although computerized laboratories require an initial purchase, in the long run, they are viewed as less expensive to maintain than human beings, who need a regular income, as well as health and retirement benefits. So machines are comparatively "low maintenance," while humans are "high maintenance."
But what about the actual purpose of education and how to talk about what is better: computers or teachers?