The podcasts and other media consumption will probably be what you will get most of the benefit from in the long term, and something like Anki and Duolingo I think are good complements for that.

Any alternatives to Duolingo that I think would be worth replacing it, would have to be something that is more focused on the specific language that you are learning, i.e. Nicos Weg for German (and I don’t personally know any for Italian, sorry). Most other general language learning websites/apps would probably be running into the same issues and limitations as Duo, and which one to use depends most on personal preference; however, there is one I’ve heard of called Italki (there may be more) which basically acts as a language exchange app, where you connect talk to people who natively speak the language you are learning, and they can give you input. I’ve never tried it, but I’ve heard good things.

Other than that, you have certified online/in person courses, but obviously those are not as convenient as Duo, and they cost money (probably more than a Duo subscription).