I am native Chinese speaker. I can help you learning Chinese. Hanyu Pinyin is equivalent to the phonetic symbols of English words. It cannot replace Chinese characters for normal communication, just as it is impossible to communicate solely with English phonetic symbols instead of English words. Because Chinese people definitely cannot understand an article written entirely in Hanyu Pinyin. This is because there are simply great too many homophones in the Chinese language.
For example, In Chinese we say "看书" (to see a book), but in English we say "to read a book"( 读书)。
We chinese never use han yu ping to communicate with each other, We used Chinese characters to do so, for example:
见到你很高兴( Nice/glad to meet you)
If you have any queries about learning Chinese, feel free to ask.