A large number of jobs exist not because they create economic value but because they make business sense given the institutions we have - customer expectations, bureaucratic regulations, and so on. They do not solve a real problem but a fake problem created by inefficient institutions. They therefore do not make our society better off but rather they represent a great cost to society - of many people's (life)time being expended on something fundamentally pointless instead of something worthwhile.
One way of spotting such anti-jobs is to compare staffing in the same industry across different countries. US supermarkets employ people just to greet customers and bag groceries, for example, which would seem a ridiculous waste of time in most of the world (hence US supermarkets are more expensive). In Japan one can find people standing in front of road construction waving a flag (they are replaced with mechanical manikins on nights and weekends).
Another way to spot anti-jobs is to to observe the effects of Covid restrictions and look for areas where removing workers or tasks made no impact on performance, or even improved it. Take waiters. In America there are around 2 million people doing this job (1.4% of all employment). The experience of Covid lockdowns shows that much of what waiters do can be done better by pasting a QR code to tables for customers to scan to visit the menu webpage and order and pay directly. Having learned this, it would be ridiculous to go back to employing people to waste their time and their customers' by doing such fundamentally needless work. We still need some servers to bring the food and drink we ordered (for now), and to bus tables, but we don't need nearly as many because we don't need to employ people to ask us what we want and then tell someone else to make it.