As a French, it’s not in our culture these “imaginary friends”. Kids don’t have them (at least I don’t know anyone that used to have one), we don’t speak about it, we don’t have stories and fairy tales about them…
I think it’s an American thing. The new movie “IF” is uncanny for me - It’s like the girl is batshit insane and I was waiting for a twist with here being in a psychiatric hospital or something.