There's a very simple solution to keeping podcasts free and open: don't buy paywalled content, and don't listen to shows that are "only available on [proprietary app x]!"

I'm going to continue supporting independent, freely-available RSS podcasts through Patreon/direct donation, and you should too. Nothing (short of ISP-level censorship) can make those hundreds of thousands of hours of decentralized, self-hosted content go away.