Important aspect is that it faster to produce then writing.
> Lectures can be a great adjunct to study but it's just not the same thing.
Popular good podcasts are not like lectures. They tend to have less information per minute and light side chats where your brain rests. They can be consumed while cleaning, cooking or going somewhere and paying reasonable amount of attention to surrounding environment. You can not do it with lecture (I tried).
You are still learning, much more then if not listening at all, but at smaller pace then expected from lecture and it requires less attention.