No, why would they be? China is heavily depending on exports. Once they are getting close to surpass USA and Europe there will likely be a shift against cheap production from China. China can only grow if the world is helping them by buying their products. Once there is a harder stand against the expansionary foreign policy of china against their neighbours we will likely see lower growth rates.
China has paid special attention to the quality during the past decade. They are no longer solely dependent on producing the cheap products but there are brands such as Huawei and Xiaomi that are producing high quality and technologically advanced electronic products. They are now trying to ensure the quality for their products, while maintaining the affordability. Both are important.
The vast majority of the world's population can't afford products from Japan or the US, because they are too expensive. I don't know about Japan, but I believe the vast majority of U.S. residents are relying on Chinese products on a daily basis. And I agree, the notion that everything from China is of bad quality is outdated. BUT, I wouldn't go so far as saying that China could "overtake" the US or any other economy. With very rare exceptions, we are living in a big family now, and all big economies are interdependent. Economies are no longer competing, rather they are helping each other to grow.