They need English at home too, a lot happens in those early years where there's no schooling and it'd be way better to know English well going into school (what ever level that happens to be at) too.
My daycare has a lot of non-native people who do not speak the local, native language with their child, at all. Still, all children (age 3, they're usually in daycare since age 1) speak the local language fluidly, thanks to how much they they spend in daycare.
No, it’s not necessary to speak X at home if you live in an X speaking country, and it may even be harmful: often children will not pick up language Y if only one parent speaks it and the other parent speaks X.
Bilingual children whose parents don’t speak the language of the community at home may learn languages slightly slower but they quickly catch up once they make friends who only speak X.
Not really. The tv content alone is all in English, the books you buy are in English, the people you talk to are speaking English. In a way or another, they get English (I have two children and we speak Italian at home, they both know English).
By the way, something nobody mentioned, once your kid learns English in an English speaking country, your English gets better (assuming you are non-native). My daughter started correcting my pronunciation and it's getting way better
