I'm not sure how you can be so confident about that. A year of Duolingo got me far enough along to comfortably follow "NOS Journaal in Makkelijke Taal", seemingly the Dutch equivalent of the RFI broadcast you linked. No transcript needed, though I do pause on occasion to look up an unfamiliar word.
Maybe you call that "the most basic grasp of a language", but it doesn't seem to have been less effective than the approach you took with French.
That's great! Maybe Duolingo has changed things up since the last time I tried them years ago. Being able to listen to even simplified native content and understand it would of course be beyond a basic grasp of the language. What were your study habits with it?
My opinion is of course just an opinion, and it's made up from all the many people I personally know that have done Duolingo for a year (or years) and would maybe be at an A2 level. It's certainly not nothing, and honestly might be better than your regular grammar first course, but I think there's more effective ways. For me it was Assimil as the primary base, which got me to reading "L'Étranger" in about 6 months. Listening to native content took longer.
I started out doing 5-10 minutes a day, building up to 30 as motivation grew. I'm still at it, 633 days later, though I'm no longer pushing Dutch quite as hard now that I'm also learning Spanish. (I figure that exposure to Dutch through youtube, reddit, etc helps me continue to learn now, anyway.)
My goals are: maintain the daily streak; stay in the diamond league; do all the "legendary" bonus levels; get all three daily quest points. That's enough work that I'm usually pushing myself a bit, but not to the point of tedium.
I'm sure that if I actually needed to learn a language, for some practical reason, Duolingo would not be the quickest or most thorough way to do it. As something I'm doing for fun, though, using downtime I'd otherwise waste on puzzle games or pointless web scrolling, it feels like a pretty good deal.
Feeling the world of Dutch-language media starting to open up was kind of magical. I'm not there yet with Spanish, but I look forward to it. How much bigger can my world get, I wonder?
Maybe you call that "the most basic grasp of a language", but it doesn't seem to have been less effective than the approach you took with French.