Aaron Trank's conclusions may surprise some. But what does the text itself say? There are in fact valid reasons to see applications of Isaiah 53 to Israel as well as to the Messiah.
First, Isaiah often identifies the servant as Israel, yet in some way as apart from Israel. In Isaiah 41:8, 44:1, 44:21, 45:4 and 49:3 the servant is specifically called Israel. Yet the servant is also given a task to Israel (Isaiah 49:5, 49:6). Many scholars see a kind of progession whereby the servant becomes a single individual, representing the entire nation, by the time we reach the fourth Servant Song, Isaiah 53.
Yet that is not the end of the story. Consider this diagram:
The left arrow is "before Yeshua." Israel was called to be God's Servant yet failed due to her sin. The servant-Messiah, symbolized by the Roman execution-stake in the middle, comes forth from Israel as the exemplary Israelite who not only fulfills the Servant's mission but atones for Israel. In that way the Messiah enables the nation, or at least the believing remnant within it, to continue to act as God's Servant, alongside believing Gentiles—represented by the arrow placed "after Yeshua." As Aaron points out in his article, it was not transparently clear to the disciples, nor to the Ethiopian eunuch, as to whom the passage referred. To say that Isaiah 53 is both/and is not to fudge on the meaning of the text but rather to show how closely Messiah and his people are related.
Second, consider 1 Peter 2:21-25, which cites Isaiah 53 not as a prophecy but as an exemplar. "To this you were called, because Messiah suffered for you, leaving you an example, that you should follow in his steps. He committed no sin, and no deceit was found in his mouth" (vv. 21-22). Jesus may be the Ultimate Servant, but this side of the cross his followers are also to pick up the role of Servant which God always intended his people to have. In the case of 1 Peter, imitating the servanthood of Yeshua means enduring suffering. Could it be that just as the Jewish people remain the people of God, their historical suffering is a reminder of the call of the Servant?
Third, notice that Isaiah 52:15 encapsulates the idea that the servant is meant to bring God's message to the entire world. In Romans 15:20-21, Paul applies that verse to his own ministry. "It has always been my ambition to preach the gospel where Messiah was not known, so that I would not be building on someone else's foundation. Rather, as it is written: 'Those who were not told about him will see, and those who have not heard will understand.' " Israel's original mission was to make God known to the world. Believers are quick to point out that Israel failed due to her sin. And yet in some ways she continued to carry out the task of proclamation, such as in the scribal preservation of the Old Testament scripture through the ages. The very existence of Israel proclaims the God of Israel. Depending on the source, it was either Frederick II of Prussia, Disraeli, Bismarck or Pascal who, when asked for proof of God's existence, responded, "The Jews, Your Majesty!"
Thus there is good reason not to exclude Israel from Isaiah 53. Israel did not die an atoning death for the world, nor was Israel sinless. Yet Peter could apply Isaiah 53 to first-century followers of Yeshua without implying that their suffering had atoning value. In the context of Scripture as a whole, Jesus the servant-Messiah will enable Israel the servant-nation to continue to fulfill her mission (expanded now to include Gentiles as well), even as in some ways she has continued to do so. Perhaps suffering has been a part of that; perhaps Jewish artists who link the sufferings of Israel to those of Jesus were on to something profound. Israel does not save, nor does the church, but the Messiah who suffers in solidarity with his people does.