That would be indeed implausible. But not every transaction happens between undeferentiated cogs.
A specific person organises the interview logistics from the company. Let’s call him Joe. When they agree with a candidate on an interview date Joe picks up the phone and calls the hotel to book a room. After that Joe calls George the trusted taxi driver they always work with. He lets him know who needs the ride and when. They exchange pleasantries. George also lets him know that the one on Monday cussed him out when he thought George was not driving fast enough. Joe laughs, and tells George that that’s crazy since he is always on time if not early. George feels good about that. He likes that Joe noticed that he is always punctual. They say good byes . Joe makes a mental note to not hire the cussing candidate.
What is implausible about this?
> How frequently are people so rude to the taxi driver that they are disqualified from consideration?
Have you met people? Happens all the time.
> Does the taxi driver get compensated?
Yes. He receives a steady supply of rides and the company pays him for that.
> Why is the taxi driver doing this?
He is a human being and those in general don’t like it when someone mistreats them. They let others know when it happens.
> Does anybody vet the taxi driver's personality testing ability?
Yes. It is called a personal connection. The driver behaves like a decent human being and only rarely say that someone was rude to them so the hiring manager believes them when it happens.
I think the reason you find this story implausible is because you are thinking on a different scale. A team of hiring managers managing 500 interviews per week for a megacorp can’t do this. They won’t have the mental bandwidth, they won’t use a specific driver, they won’t have the personal connection. Not every company is that size. Some company might only interview a few people a week.