The same is true for physical keys for cars, houses, lockers, etc., which is why people have an intuition to test out keys to make sure that they work.

Most people aren't going to do that for the standby keys. And while they test out the real keys, they mostly don't go from working to not working because someone did a garbage collection/unused keys pass or failed to update some field or deleted something on a server.

Yup. Instead they stop working because of rust, corrosion, wear & tear, or heat distortion from improper storage...

There seems to be an obsession that if a digital key doesn't comprehensively solve all problems, it's terrible, despite the empirical evidence that people are fully capable of using physical keys despite their limitations.