That goes hand in hand with a level of trust with some companies/people and everyone has different threat tolerances. It also highlights the mindset that you have no idea what the person on the other end of the message is doing with it. End to end encryption helps keep in line eavesdropping down but if the recipient of the message has a compromised device or are screenshoting everything and posting it on facebook it’s out of your control.
AudioBookShelf is a beautiful podcast option. OP would have to fully migrate into it but once done it’ll let you listen to an episode on pc, pause, then resume from the same spot on mobile. It’ll auto grab episode as they come out and store them on your system for streaming or local access. The android app is pretty good and i know webapp works well on ios