They've been telling us (in the US) for the last two decades that
the Boomers retiring will tank the economy. A lot of the missing workers have retired, which means they're just chilling at home blissfully ignorant of what's coming down the pipes for them.
At least 1.5 million of the missing works in the US are women who've stayed at home, because the sad truth is that most women hold a job just to pay for childcare. Households with a man as primary earner and a woman handling the house and kids used to be how things were done, and it actually requires real resources to go against that grain even now.
Beyond that... well, anyone getting fired for not getting the jab probably has several months on unemployment coming to them. Not to mention there's ways to get other benefits too, as well as ways to work under the table or for yourself.