I know only a few people in my country (in Hungary), who make a living with YouTube. Much more people do it in the USA. Most people in Hungary earn a pocket money with YouTube. The location of the audience is an important factor. The advertisement clicks coming from people, who live in the wester countries worth much more than click from people, who live in eastern countries. And if you make content in English, then you can reach a worldwide audience. Many Hungarian people create content only in Hungarian. They usually do not reach a worldwide audience.