They went to a subscription model for using the desktop app... If we could buy it at once as it was possible before I wouldn't even be looking for alternatives, but I despise subscriptions.
Funnily enough (although I haven't looked thoroughly) I couldn't find a way for this yet 🏴☠️
I thought I could synchronize what I was listening to and where I stopped with gpodder.net but this never worked because I never understood how to use it, even though I logged in on both desktop and phone, so I had to give up the idea of listening on the desktop and I only listen on the phone. If I am at home I sometimes connect to a Bluetooth speaker to have a nicer experience.
I ended up using the nextcloud gpodder sync app, works a treat, there's even a nextcloud app for listening to podcasts in your browser, so I use that for desktop use.