That's not mostly true as some countries products aren't dependent on china as source of spare parts. Yes, you're right that other countries import goods from china but so is china and that's the nature of commerce. But Japan and Korea are some of the countries that are independent on their goods and not mostly rely on china and other countries.
I have personally confirmed this. Even if you check your Korean and Japanese mobile phones, you can see that the screen, battery.etc are made in China. As far as I know, Japan never had any large manufacturing units producing mobile batteries. From the very beginning, they are importing them from China. Also, many of the electronic components need REE (rare earth elements) for their manufacturing and these deposits are found in few regions outside China.