In Canada there is a system for evaluating the language skills of second language speakers called the Canadian Benchmark system. This program is no doubt the result of a lot of work by many people working in committees. According to this system language learning skills are divided into 12 different levels, all carefully defined in ways that most laymen would have trouble understanding.
I cannot see much practical benefit from these benchmarks other than the need to classify people for the benefit of classrooms and teachers. However, if a person is really motivated classrooms are not that useful. If a person wants to learn a language they need to find content of interest to listen to and read and people to talk to. There is enough content available in stores, libraries and on the Internet. There are tutors advertizing themselves or they can attend a class. If they are motivated they will soon outpace the other learners in the classroom. If they are not motivated they will not learn much no matter where they are.
So the benchmarks and other similar testing really sidestep the fundamental problem of how to motivate the learner. If the learner cannot be motivated it is almost not worthwhile trying to teach him or her, benchmark or no.
Today there are ways to make a vast corpus of content accessible to learners in such a way that learners can choose content of interest, at their level, and systematically learn the words and phrases they need. Of course this assumes that the learner is motivated.