There are 23 million YouTube channels. For every one podcast, there are 32 YouTube channels. There are somewhere between 600,000 and 1,000,000 books published each year in the US alone.
I don’t think there are too many podcasts. I believe there are two many bad podcasts. I’m not making this up, one podcast I found started off with the host putting his phone on a table while he and his co-host ate pizza at the mall. They then talked about what they may or may not talk about on the podcast ( a great conversation to have BEFORE you press record). Also, many people feel that the number of podcasts that have published in the last 90 days, that number is closer to 250,000.
In the past, when you paid for media hosting, if you quit your podcast you would cancel your hosting and the podcast would be eventually be removed from the directories. Now with free media hosts, a person can record one episode at the mall while eating pizza, and decide podcasting is not for them, and that awesome piece of content lives on forever.