Indeedy.
It falls first and foremost to the airlines to operate above board.
They are checked by the authorities who set and enforce the rules.
Neither of this is of any concern or culpability to the pax, who simply pay a fare to travel to a destination. The vast majority of whom give less than 2 hoots about how this is achieved as they're under the impression that the airlines operate lawfully and the authorities operate to catch the unlawful.