It is not always case. My hubby is an engineer, so he has plenty Indian/Pakistan and Middle Eastern friends (they're all engineers and physicists in many different fields). They all speak English very well. Their first language is not English. They are quite educated in graduate/ph.d studies. But some lack practical skills. They can pass car written exams easily and can read signs doesn't mean they're good drivers.
My hubby's friend is in Ph.d engineering program and he needed a car to drive to an airport to other city because he missed a airport shuttle van. Hubby was going to let his friend borrow his car, but he wanted to test his friend's driving skills first. Well, his friend failed a driving test because he didn't bother to check his blind spot before changing the lane. He almost hit a semi-truck and other car. Hubby managed to reach a steering wheel to veer a semi-truck. Semi-truck driver was mad and honked. lol
Hubby had to explain it to him that it was always important to check your blind spot before you change the lane, but you know what his friend said? "That's what the mirrors are for."
My old friend's wife is a Korean, and she thinks she owns all of the roads. She can speak English and read signs, but her attitude... eh.. If you stop at red light and see no other car anywhere, you decide to run a red light anyway. The cop pulled her over and lectured her to not run a red light, but she complained to a cop that there is no other car anywhere and she had to wait for red light to change, and she thought it wasted her time. It wasn't her first time.