Is there a feature you want out of the paid subscription, or do you just want to support them? The subscription goes towards enabling features which have an ongoing cost (sync of files and listening state across devices so you can listen on desktop where you left off on mobile). I don't think they want to offer a one time fee for what is an indefinite period of cost.
AFAIK most features other than that are still fully supported in the free version of the app without ads though. So if you don't want any of those features, they're probably better supported by you recommending them to others than giving them a few dollars.
Yeah, I mostly just wanted to toss them a few bucks since they've created an app that I really love. That's a good point, though -- I've recommended Pocket Casts to a lot of folks at this point, and pushed several off of listening to podcasts on Spotify so I'm doing my part to contribute in small ways.
AFAIK most features other than that are still fully supported in the free version of the app without ads though. So if you don't want any of those features, they're probably better supported by you recommending them to others than giving them a few dollars.