So, I was seeing a video today where the narrator brought this approach as the best for L2 acquisition. I believe it can be useful, that's how we all learned our L1 after all, but I wonder how it can work and if it works if we are involved with L2.
The issues I'm concerned with are mainly two: 1) comprehension, 2) speed.
We really did learn our L1 by mostly associating images to the words but I feel we can't base our acquisition on this. In a natural language acquisition approach, we are always misunderstanding things and in the end actually understanding very little. For example, I had a "natural" japanese lesson and the teacher played a couple videos and after commented on them, telling us what he believed we could have got from the dialogues. Most things he said I didn't get at all. As kids it was okay if we didn't understand much of what others said, but as adults neither can we or the people we talk to tolerate that.
It generally takes at least over 5 years for us to acquire our L1 to communicate our thoughts sufficiently well for day to day life. At 5 we weren't masters of the language though, as we probably didn't know how to create many words, how to organize words in a coherent way, which words to use and so on. Past that age we needed a couple more years to get to hone our skills, resulting in over 10 years of "natural" language studying. The average L2 acquisitioner can't work with 10 years, as most of us need to learn a language for something that requires the knowledge as soon as possible.
I hope you enlighten me about these issues in particular as some people claim to have turned into 10 lang. + polyglots with this approach despite of what I said.