You wrote: "Why do you assume everyone in the world has native english speakers as friends, willing to do free proofreading?"
So you didn't write that? Ok.
The people who proofread my work aren't in my immediate circle of friends. My point is that you can find people out in the world that aren't in your current bubble.
I have access to people now who speak and read more languages than I ever will. Some of them are in Russia. I think you are inadvertantly placing limits where they may not really be.