I remember one employer requiring for a mobile developers five years of experience with Swift.

At the time of the job offer, Swift barely existed for more than two years. Probably shit made by incompetent HR, same company had other jobs that required, of a webdev, stuff like Cisco certs and FUCKING COBOL AND CICS. That's like requiring of someone to work in catering to also have a HAZMAT truck driver license and experience in operating a lathe.

kind of, they want people to apply that are under-qualified from what they demand so they can get away with paying them less than advertised.