That's complete bunk. I was fluent in English by the age of 7-8 entirely from having watched a ton of TCC (a British kids channel) on my own. I'm sure adult aid helps, but it is in no way necessary.

I'm from Sweden btw

I think the original comment applies to one’s first language, as opposed to later languages

That's right, and also to very young children, like 2-4. 7-8 year olds are very different.

Many Europeans told me they learned English from watching TV as children.

Complete bunk is brandishing one's own anectodal evidence to try to invalidate scientific consensus based on a few decades of countless studies.

Seconded. In my case it was The Secret of Monkey Island, Dune II and an insatiable appetite for more digital worlds to escape into - PC Format, Pc Gamer magazines...

Years ago, a friend of mine was thrilled with Sesame Street, because after watching it for a year his daughter learned most of her letters and could count to 10.

I replied that sounded like the most inefficient method of teaching ever devised. Not what he wanted to hear :-)

IINM there are several of these.