Did you all know that all of the languages are currently all of the same difficulty?

Last month I asked a similar question, but I didn't know at the time how common it was for people in the language learning industry to say that all languages are equally difficult. Upon further research I found that this is currently the standard view. The scientific study of language acquisition, second language acquisition, and bilingualism, which was born from the ashes of the Chomsky debate with behaviorist B. F. Skinner, has concluded that all of the world's languages are equally difficult. <br><br>This is why S. Krashen says that "The human brain is able to store as much as it needs to." (Hence, the ranking of difficulty for different languages, which was a prominent aspect of Stephen Krashen's affective filter idea, is currently all but worthless.) This is why Mark Manson says, "What if all of the languages are currently all of the same difficulty?" <br><br>This is why the US Foreign Service Institute, which provides the ranking of difficulty for different languages, is currently saying, "Although it is difficult to rank languages, and the challenges of learning different languages differ significantly, the consensus is that the difficulty of different languages differs significantly." <br><br>And, lastly, this is why V. Cook says, "No evidence has been discovered of a language that falls outside the boundaries of the flexible template of human language," and "All of humanity's languages are the same in terms of their flexibility and their arbitrariness." <br><br>Or, as Chomsky put it, "We are born pre-equipped with all of the machinery necessary to learn languages." And, "The knowledge and the ability to learn and speak any human language exists in everyone, and it is completely innate." And, "We know that human language is completely flexible, and that it is constantly changing." And, "Human language is completely arbitrary, meaning that there is no logical connection between the meaning of words and the sounds that are used to represent the words." And, "The ability to learn and speak any human language exists completely within everyone." <br><br>So, currently, difficulty is measured by the similarity of the target language to the learner's L1. <br><br>Note: difficulty is measured by the similarity of the target language to the learner's L1.