Is Trustpilot a global or only United States specific product review platform?

Any chances of making it a global product review platform for products and services that originate from other countries as I see only countries participating in it. The platform has a database of a product's or service's official website than the product or service itself. Why is that so? What about the products or services that do not have an official website? How are those products listed on the Trustpilot platform? How reliable is the information (reviews) available on the Trustpilot platform? Who are the users or consumers who write reviews on its platform?