Comment by seszett

I'm also a French speaker living in Flanders with a Flemish partner, and children who speak both languages.

I'm pretty sure the ease of speaking English for Dutch speakers comes mostly from the closeness of the language (as evidenced by my comment on people who watched French-dubbed anime as kids, not Japanese original or English-dubbed). And TV content for children (including De leeuwenkoning or Een luizenleven, to take examples from the article) is almost universally dubbed in Dutch as far as I can tell.

My personal opinion is that watching movies in English is really not as useful as people think it is, it does help once you already know the language but children just don't pick up a language by watching movies in that language without having already some basic knowledge of that language.

IMO (but it's starting to get off-topic) it's more generally Latin languages that are a hindrance for their native speakers for some reason, and globally Latin speakers are just always bad at learning other (non-Latin) languages, especially at speaking them. But it's not because they're watching Le Roi Lion rather than The Lion King.