Technology replaces jobs all the time. It just makes people more efficient. One person can do the job it used to take 2, 3, or 10. But more jobs became available. Like you said, there are 8.2 billion people now. And now there are billions of jobs. But there were only 4.8 billion people 50 years ago. So half as many jobs (roughly). And look at all the technology that came into place in those 50 years, making people more efficient, yet still there are twice as many jobs now (roughly)

The trick is to be useful and always be willing to learn the new stuff. Don't get stuck in a rut saying things like "we never needed computers back when I was working in " those people get replaced because they refuse to be fluid.