Right now you are reading English. That means that you are using your brain in a very active way. Reading is a very active process. It is true that the writer does a lot of work, but the reader also has to work hard. When you read a text, you have to do some or all of these:
When you learn a language, listening, speaking and writing are important, but reading can also be very helpful. There are many advantages associated with reading, including:
You will usually encounter new words when you read. If there are too many new words for you, then the level is too high and you should read something simpler. But if there are, say, a maximum of five new words per page, you will learn this vocabulary easily. You may not even need to use a dictionary because you can guess the meaning from the rest of the text (from the context). Not only do you learn new words, but you see them being used naturally.
When you read, it gives you a good example for writing. Texts that you read show you structures and expressions that you can use when you write.
When people write, they usually use "correct" English with a proper grammatical structure. This is not always true when people speak. So, by reading you see and learn grammatical English naturally.
You can read as fast or as slowly as you like. You can read ten pages in 30 minutes, or take one hour to explore just one page. It doesn't matter. The choice is yours. You cannot easily do this when speaking or listening. This is one of the big advantages of reading because different people work at different speeds.
If you choose something to read that you like, it can actually be interesting and enjoyable. For example, if you like to read about football in your own language, why not read about football in English? You will get information about football and improve your English at the same time