Because most of the CS/CEng content is in English, not knowing english is a huge disadvantage.
Now I am shocked that you are shocked that s/he is shocked.
Now I am shocked that you are shocked that s/he is shocked.
If you’re not interested in an international careeer (many people aren’t), you have quality education available in your local language, and there’s a thriving local tech scene I don’t see why it has to be that much of a disadvantage.
There are many other languages that are big and used by tens of millions of people. In most of those languages you can find all the books, courses, and conversations you need to take up computering.
You can of course find the answer in your native language also, but it will be less likely it exists, it will be harder to find, and less "peer-reviewed".
There are tons of resources in other languages but you wouldn't aware of it, you wouldn't even know how to look for it because you don't know the language.