> Maybe it’s my personal bias but it seems a lot easier to learn other things than language as an adult.
I started to speak properly when I was 4, I was a bit late. But imagine the following:
You'd go to a country that you don't know the language of for the next 5 years. You can assume that you don't need to worry about your survival as food, water and shelter are provided for you among some luxuries like internet. Basically, you achieved financial independence.
The challenge becomes: in this new land you have to learn the local language within 5 years. There is, however, one caveat. You are only allowed to interact with the local population in their (spoken and body) language. You're not allowed to use any other educational resource. In other words, you have to learn a new language exactly like a baby does.
Could you do it in 5 years?
I bet if you set your mind to it, you really could.