People in some industries that are typically low paying, have left those jobs for good because they have found other jobs with better pay, better benefits, etc.

The Great Resignation: Why Millions of Workers Are Quitting Their Jobs : NPR

Additionally, yes, many people died.

Additionally, yes, many people are still dealing with long-Covid symptoms that can be truly disabling. I suspect we'll see many people being added to officially disability due to long-lasting effects of this illness.

Additionally, yes, many people cannot afford to go back to work. They may have lost a spouse and now cannot afford to pay for childcare and work, for instance. Or, they have opted to keep their kids home for schooling because kids have not been eligible for vaccination and they've made the choice to keep their kids home where they feel they are safer.

Additionally, many of the people who lost jobs have not been able to find comparable work. For instance, older people who might have been gainfully employed, were laid off, but finding a job as a late 50 or 60 or 70 something is very difficult.

There are many reasons people aren't working. That doesn't mean they are able to support themselves well either. People are struggling.