At present, long-form reading is reserved for something you care so much about you will do it to the exclusion of other things. Podcasts are for things you only care enough to pair with another activity.

Never in my life have I seen or heard of someone who sat down to exclusively listen/watch a podcast.

Long-form reading requires undivided attention to something important, while podcasts are often enjoyed alongside other activities. It's rare to see someone solely focused on listening to a podcast.