minhag - After the Men of the Great Assembly established the 'Amidah', was it an obligation to recite it before the destruction of the Temple?

On Megillah 17b : Rabbi Yochanan said, others say it was taught in a Beraita, that 120 elders including many prophets established the eighteen blessings in the order that we have today.

Before the destruction of the Second Temple, was there an obligation to recite the Amidah like there was after: "Shimon HaPekoli arranged the order of eighteen benedictions before Rabban Gamliel at Yavneh. (Brachos 28b) ?

According to R. Berel Wein " ... the leaders in Babylon codified a system of prayer that substituted for the Temple service. They based this on the prophetic verse, “Our lips will substitute for sacrifices” (Hosea 14:3)." After the exile (Babylonian) would this formula (The Amidah?) have been obligatory since there was a new Temple?

Regarding the seeming contradiction of the Amidah being instituted twice, from Wikipedia: In order to remove the discrepancies between the latter and the former assignment of editorship, the Talmud takes refuge in the explanation that the prayers had fallen into disuse, and that Gamaliel reinstituted them (Meg. 18a)