'Quiet Quitting' at work: What's the cause, what's the solution?

Alarm bells are ringing in many HR departments amid an apparent rise in disgruntled employees "quiet quitting" at their workplace. The question: What's it all about, and is there a solution? As a rule, preceding this stage is a phase when the employee had once shown a willingness to work and engagement. "People want to do a good job, but if they are always being discouraged this can lead to inner resignation." What's good about it?