I had an Xbox hooked up around 2002 at a friends house (high school years for me) and their father commented that Dead or Alive looked like a movie to them. They didn’t know how games could look more realistic.
Graphics programmer has got to be up there with chef and prostitute for evergreen, recession-proof careers. And the nice thing is, the tech doesn't even change that quickly. People are still using OpenGL, the original version of which was released before DOOM!
Whether it's recession proof or not is a fairly open question, one thing for sure is that it's not layoff proof. Game companies are notorious for doing mass layoffs or shutting down with little to no advance notice and as a game developer you can never be too sure about your job security at any one company, not to mention it's kind just accepted that you will be working longer hours for less pay.
As for the notion that the tech doesn't change that quickly, that is simply false. Graphics programming is unbelievably cut throat, competitive, and advances very fast. Not only are there advances in technology, but different games also have different aesthetics that often require very niche or customized development to get just right so as to avoid your game feeling generic.
Graphics APIs and hardware change almost every other year and the major titles have to adapt to the latest features. You can certainly make good games without focusing on graphics, plenty of good indie games or games that don't focus on graphics, but if you are a graphics programmer and your game does focus on that, you are constantly having to keep up with advances in technology.
Crazy how far we have come since then.