For me, it's strange. I come from a francophone family, but always went to school in Dutch. My Dutch is splendid, like on C2-level, but my French ironically only is on B2/C1-levels.

That's because my parents are working class immigrants who didn't go long to school, so it's not as if we had high-inteligence conversations at home about politics, history, physics, philosophy, etc.

Also, I much preferred watching American movies with Dutch subtitles, rather than American movies with French dubbing.

I do however watch many French Youtubers, as I can understand them perfectly. But I never read French books or news articles. And I find that you really develop your language vocabulary by reading, rather than listening. I understand 99.9% of spoken French, but only about 95% of written French. Especially the past tense, like 'il fut/il mourra' etc. No one speaks like that in real life. there are even worse examples. The passer simple of pouvoir is 'tu pus' and 'vous pûtes'. Lol! When I read that, I think it means 'you stink' and 'you whores', but it means 'you can'