No. They are standardized international and local tests. There are enormous fraud problems in all sectors, including this one. For example, impostors sometimes show up for the tests.
When I was starting my career, visa officers were the ones who determined people's language proficiency, and they did it in interviews. It was not professional at all, nor was it objective. Each officer had somewhat different standards. They chatted with the person for a certain period of time, and then granted points on that basis.
In 2001, the government changed the approach and started using standardized tests to allocate a certain number of points based on linguistic proficiency.