Ge’ullah and tefillah

The first half of Masekhet Berakhot covers two main topics, the Shema with its blessings and the Amidah. One subject arises multiple times as a glue that joins the two topics together (five times, to be exact, according to the Bar Ilan Responsa Project: on 4b, 9b, 10b, 26a, and 30a). This is the requirement to be somekh ge’ullah li-tfillah—that we connect the redemption at the end of the Shema’s blessings, “ge’ullah,” to the start of the Amidah, “tefillah.” The Halakhah gives this requirement high priority.

What is the reason for semikhat ge’ullah li-tfillah? And why is it so important?