Not perfectly efficient, but generally pretty efficient, at least when there aren't major externalities unaccounted for.
Yeah, there might be some jobs like carbon capturer where the market is not set up in a way for you to get payed for your service despite its vast value to society.
However in the case of flipping burgers, if people aren't willing to spend enough on a burger to pay the salary of a burger flipper, then clearly the job of burger flipping is not worth doing.
We could argue hypotheticals. I prefer some concreteness.
I'm not finding much by way of specific sectors affected, though healthcare, education, transportation, and hospitality (foodservice, lodgings) are often mentioned.
US Department of Labour has a breakdown by state, showing proportionately more quits in less-populated states:
(What we want isn't a list of openings per classification, but deviation from normal levels of openings, adjusted for total classification size. Stats are ... complicated.)
One job category that could desperately use greater competene is business and economy journalism. The number of useless articles rehashing opinion and generalities on this topic is too damn high!
