I'm also curious about this. My guess is the monetisation is different and podcasts are way more lucrative. - tracks are paid by plays straight from Spotify but (I think) podcasts instead rely on advertisements.
From the article
> Anchor manages the commercial load and pays Moore $12.25 per thousand listens
which works out to ~$0.012 per listen
And from the top result on Google for "how much does spotify pay per stream"
> $0.0033 to $0.0054. That's how much money Spotify paid artists (through their rights holders) per stream in 2021, according to Insider. That means it would take roughly 250 streams for an artist to earn $1.
Also maybe the advertising value varies considerably with the number of podcast listeners and the specific advertisers partnered with, whereas the track stream amounts are probably pretty static.