I agree with both of your premises. I started going to International school when I was 10 and got all my education in English. I got two college and one masters degrees. I am fairly confident in my ability to use English yet my wife is American and every day she finds something to correct in my English.

My wife have been learning Turkish using Duolingo and a Turkish learning platform for the past couple months, and she can hold her end up in basic conversation. We have many expat friends who have been learning Turkish for a year or so and they can communicate pretty well.

Turkish syntax is wildly different than English syntax, and pronunciations are throat based rather than tongue based. There are lots of synonyms and parallel meanings in everyday use. Moreover there are not many resources to learn Turkish from. Yet, people start speaking broken Turkish enough to communicate complex ideas within a year.