But the deal wasn't Google giving Apple $1B to be the default search on iOS. It was Google giving Apple a 34% share (perhaps - it's still a bit unclear in the article) of iOS search revenue. It is still a deal
worth ~ $1B, but not a deal for $1B.
The context is important. If the number is 34%, then Google's iOS revenue would be around $3B, of which Apple got a cut.