To this of course I might offer this

https://medium.com/@chacon/mit-scientists-prove-adults-learn-language-to-fluency-nearly-as-well-as-children-1de888d1d45f

Oh, the cost of believing everything we read. I hear you. At some point, when we simply go DO, we end up being fine. At 58 I learned a good bit of Thai. Hell, Spanish would have been much easier.