Does not the non-practice of the Hadith before their compilation indicate their lack of legal obligation?

Knowledge and action regarding the Prophetic Hadith did not cease until its codification; Muslims preserved it and acted upon it since the era of the Companions, even before codification, and transmitted it in their gatherings and circles of knowledge. The Companion Jabir ibn Abdullah would travel for a month to seek a single hadith. Codification came later to preserve and authenticate the Sunnah. Similarly, the Quran was not compiled into a single mushaf during the time of the Prophet, peace be upon him, but was preserved in memories and written down in scattered pieces, and then compiled for fear of its loss. Therefore, to say that Muslims did not act upon the Ahadith before their compilation is an error.