I would actually have no problem saying that a podcast that stretches your critical thinking muscles makes you "smarter". But do any of the listed podcasts do

I would actually have no problem saying that a podcast that stretches your critical thinking muscles makes you "smarter". But do any of the listed podcasts do that? To work a muscle or your brain, you have to actively...well, work. I haven't tried all of the podcasts they listed, but of the ones that I have tried, they're all passive entertainment. (And again, nothing wrong with that.)