The Bible is not primarily about you is correct. Man’s sin is the central problem that creates the tension in the biblical story is correct. But the way you phrase the rest is not great. The Bible isn’t about Jesus” “Jesus is not the main character.”
This directly contradicts Jesus’ own interpretation of Scripture and the consistent insistence on a Christocentric reading. John 5:39: the Scriptures “testify about me.” Luke 24:27, 44–47: Jesus interprets “all the Scriptures” (Moses, the Prophets, the Psalms) as concerning himself, his suffering and glory. The plan of redemption is the eternal counsel of the Triune God (the pactum salutis or covenant of redemption). The Father elects and sends, the Son is sent and accomplishes, the Spirit applies, but it is one undivided work of the one God. creation → fall → redemption → consummation, with the glory of the Triune God as the end and Christ as the central actor in the drama of redemption.