Some exams in the UK (GCSEs) moved away from coursework because of the problem of cheating. If it happens with GCSEs, why would it not happen with high stakes

Some exams in the UK (GCSEs) moved away from coursework because of the problem of cheating. If it happens with GCSEs, why would it not happen with high stakes professional exams? There are some IGCSEs that you can take remotely (with a camera on you and a hefty extra fee) and I am wondering what problems those will run into. Pearson are offering them.