Hanyu pinyin (or pinyin) is the de facto standard for transliteration of Standard Chinese, especially for materials using simplified Chinese characters. In the last ten years, I have used or browsed textbooks, dictionaries and other learning materials; some of them were entirely in Chinese, others were for native speakers of English, German, French or Dutch. All of them used pinyin as their transliteration system.
I have also met learners who found pinyin non-intuitive, especially for the sounds represented by
c. I have known people who devised their own transliteration system but abandoned it some time later.
If you don't want to use pinyin, you will have a hard time finding learning materials for simplified Chinese characters that use a different system; these materials are available but are typically at least thirty years old.