Yes I agree, the Spotity is missing a lot of high quality podcasts for no apparent reasons. Not only are many quality podcasts missing, but podcasts that previously existed in Spotify have disappeared.
For example, "Science Friday" is a podcast that I had previously been "following" with Spotify, but this podcast has disappeared altogether from Spotify podcasts I "follow". Further if I do a search on this podcast, it does not appear at all. Instead Spotify search on "Science Friday" shows an empty Podcast with the name "Undiscovered by Science Friday"? On my mobile devices/tablets it just shows ERROR. As a result, I've had to go back to Google Play to listen to my podcasts.
Early in 2019 many popular podcasts started to regularly appear in Spotify. This lasted for a few months, but then these podcasts seemed to disappear.
For example up until April 5 2019 episodes of Science Friday appeared weekly, but after that episode, they no longer appear.
This issue is not platform specific, for example episodes of SciFri after 4/25/2019 do not appear in the iOS Spotify app, nor in the Desktop apps, nor in Web Browser interaces.
To be clear, the issue is limited to Spotify, for example Science Friday episodes regularly appear in Goggle Play, Apple Music, and other apps (they didn't stop carrying these podcasts). What gives Spotify?