What you say can be true about a static isolated system, though. My employer has a Windows XP computer still running a machine in our factory. The PC was built built in 2006, connected to the Internet once upon deployment then disconnected thereafter. It has been running the software and machine more or less untouched since, receiving zero updates, performing it's duty as it was built to.
But then, how would they get a duplicate of the ignition key?
https://blog.nuoplanet.com/en/long-range-rfid-readers
Since at least 2009 it has been possible to duplicate keys using photography, a hobbyist replicated the work in 2018. So take a photo when the keys are out somewhere; on a table, or when unlocking the car.
https://www.schneier.com/blog/archives/2009/10/reproducing_k... https://hackaday.com/2009/09/22/photographic-key-duplication... https://markhedleyjones.com/projects/duplicating-keys-from-p...