I'm a frontend engineer for the one of the big 4 tech companies, so I'm not really concerned. I'm in my 30's now, and don't expect to be coding for the rest of my life, but is the field going to become so constricted that 30 years from now wages will stagnate? I doubt it, at least not in the grand scheme of things.

At the end of the day, I'm not going to plan my life around my job suddenly becoming less valuable.