The podcasts and other media consumption will probably be what most benefit you 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 significantly more than even a Duo subscription).

EDIT: Oh, I forgot to mention, but one thing which I personally enjoy is looking up and trying to read children's books; and I mean like "90% picture & 10% text" books which are made for parents to read to their very young kids. And as you get more comfortable, try finding and reading increasingly harder books/stories online.