There is a wide variety of English language tests in the market and they have been built differently. Some tests are designed for academic purposes while others are more suited for migration or a more professional context. When these English tests are misused in its applications, it reduces the validity of the tests.
Take a real-life case in the UK, for example, where overseas nursing recruitment has halted because native English speaking nurses are failing IELTS. IELTS was not built for healthcare communication and assessment and the content of the test has little relevance to the healthcare sector. Now, Occupational English Test (OET), a more appropriate English test that was built for healthcare profession is recognised for professional registration in the UK.
It is important to look at the right English language test that is most suitable for your goal.