People have a tendency to believe that any current trend in technological advancement will continue forever. Maybe that's true in some cases, but more often engineers start to run into real physical barriers and progress slows or stops. We will, unquestionably, all be displaced by computers if processing power continues to double over and over again, but will it? Moore's law is not an actual law, its a joke that became an industry benchmark.
Read old science fiction from the height of the space race. There was once a time when science fiction writers, even the ones with physics degrees who should have known better, were absolutely sure that in a generation we would be living on at least three worlds, and that computers would always use punch cards. People are not good at predicting the future. Maybe computers will displace our entire profession, or maybe processing power will hit a hard wall and we'll stall, or maybe some other unimaginable advancement will happen and our salaries will triple while a different industry collapses. I don't think we know.
Bringing that back around to this thread, BTW, people are also really bad about predicting the future of physician salaries. Maybe this profession will collapse tomorrow, but everyone thought this profession was on the verge of collapse 10 years ago when I started medical school and real physician salaries had been decreasing for almost a generation. Certainly no one thought that salaries would rise by 10% per year for a decade. If you had told someone 10 years ago that you were hoping to make 250K as a Pediatrician they would have laughed at you, now that's barely above the median full time salary.