And it's closer to Frisian than Dutch. If the Battle of Hastings hadn't happened, these languages would be easily and mutually comprehensible. But that just shows that English descends from a branch of West Germanic. It changed gradually over time, kept a core Germanic vocabulary for its basic terms, and borrowed a lot from other languages as it needed more complex concepts, moreso than Modern High German which allows for easy word invention through combination.

Creoles are defined as languages emerging from pidgins, which themselves are often simplified forms of speech that allow linguistically separate groups to communicate. English is not that. It has an unbroken line of native speakers whose usage gradually evolved, while maintaining a system of complex syntactic rules as well as a literature.