“Podcast” is more like “VHS” than like “movie”. Podcast is a format. There are lots of ways of listening to prerecorded audio. It’s only a “podcast” if the medium is similar to RSS+file. Otherwise, it’s just a show. Is an SVHS or some other extended format a VHS to a layman? Sure. But a DVD is not.

No it isn't.

Its a particular type of entertainment product that is completely divorced from its distribution method.

I could burn a podcast onto a CD and it would still be a podcast.

I once heard of a rich man who had his assistant burn podcasts onto CDs for him to listen to in the car. I don't think it would be normal usage to say he is a "podcast listener" though. When people think of podcasts, they think of someone using the internet to listen to audio, not a weirdo rich guy with assistants to do the dirty work of learning new technologies.

Would you say that a rich guy who has his assistants send emails is an email user? For example, it has been speculated that Trump has never sent an email.[1] But surely they didn't mean he's never had an assistant send an email. They mean he never used the application to do it himself.

[1]: Somewhere in this long discussion https://bloggingheads.tv/videos/58089

Language is flexible and user driven, but parts of how people use language is to defer to expert users for fine distinctions while making the broad categorizations themselves. Experts have determined what is and isn't a "monkey" but it's sort of an absurd category because it has to carve out homo sapiens but include old world and new world monkeys.

In this case, users might not know that podcasts have RSS behind them, but they certainly know that a podcast is prerecorded audio delivered over the internet and they somewhat defer to experts about the formatting, the way that they would agree that a "Betamax" is not a "VHS" but an "S-VHS" might be a "VHS" to a layman.