Why does the author think it's a one way system? First, let's get this out of the way:
"the golden era when Americans could get a job, keep it, and expect to retire with an adequate pension are over"
That age ended in the 1960s, or maybe even in the 1950s.
"workers are beholden to employers"
Actually, it goes both ways. In the US, afaik two weeks notice is pretty typical, if you get fired. That surely does lead to insecurity. But it goes both ways: you can also leave your job on two weeks notice. With a bit of accumulated vacation, you could effectively be leaving from one day to the next. If you're an important employee, holding critical responsibilities, that leaves your employer in a really shitty position.
Any company in the US could adopt a different model. Just as an example, in much of Europe, you have to be given three months' notice that your employment will be ending. Would that be better? Do note that this goes both ways: if you are unhappy with your job, you cannot just leave. You must also give three months notice, continuing to do you job, and giving your employer a chance to bring in your replacement and arrange for a smooth transition.
Both models have their advantages and disadvantages. Personally, I prefer the European model - it gives more stability. But it does reduce flexibility and mobility, both for companies and employees.