How many years do you usually practice in Korea?

Of course, some people say that sm can't get out and may become a broker or something. It is not easy to be a trainee in Korea. You see, many artists have practiced for 5-7 years before they debut, some for 3-4 years, and they may be lucky to debut in 1-2 years. The chance is very small, and yg may be longer than sm, so many people can't stick to it if they really want to practice.