The eternal plan of God to put on display His wrath, anger, justice, grace, and mercy implies Christ did “have to do it.” The having to do it was always the plan for redemptive history.

A similar issue would be saying there was no purpose for the existence of evil. Instead, God (if He always knew it) solved the problem with the crucifixion of Christ for redemptive history. But it was always God’s plan to ordain evil for the use of/the end goal/the purpose of ultimately revealing His grace to the praise of His glory for eternity.

This doesn’t necessarily mean God experiences time as humans do in this life (linearly); rather time is an ever-and-eternal-present. However, the divine calendar and timetable of the crucifixion of the Son of God was set in eternity past and accomplished in human history.

Additionally, the prophets penned the words of the prophecy about the coming life, death, and resurrection of the Messiah, the Lamb, the Son of God. The long-awaited Messiah was expected to come, but most had a problem with His death (even His own disciples—like Peter attempting to behead an officer/guard in Gethsemane when they came to arrest Jesus). But it was a necessary death to a necessary plan in the eternal mind of God that was accomplished in the Son of God.