The article only anecdotally makes the claim that there was a downturn in podcast quality and listenership. I doubt that this actually happened. Instead podcasting has slowly been bubbling away and has now really broken through to be a more mainstream activity since it is a lot easier. I certainly never stopped listening to podcasts. We used to have to sync podcasts manually over USB to our iPods. Now we can download or stream them on the go with our smartphones and send them to the cars sound system via Bluetooth. Technology has gotten incrementally better until we reached now, where podcasting has become really easy.
This. Most of my current favorite show aren't new, some goes back to pre-2006 era. For me the game changer is the Podcast Addict[1] app, but it mostly just allows me to have a bunch of "listen sometimes" shows. For the good ones, I won't care if I have to download to PC and sync with my phone, like I didn't complain much when I have to go to a physical store to buy CD back when it's still a thing.