Unlike the commentaries of R. Hananel, R. Gershom, or the other various commentaries that preceded his commentary, Rashi’s method highlighted key phrases in the talmudic discussion (dibur ha-mathil) instead of the paraphrasing commentary style of the aforementioned scholars. His commentary quickly spread throughout France and Germany, replacing the previously utilized commentaries. Now that the Talmud had found its authoritative commentary, a path was laid for the Tosafist enterprise.
Aryeh Leibowitz, “The Emergence and Development of Tosafot on the Talmud”, Hakirah 15 (Summer 2013), 146, n. 6.