Any time in Isaiah the metaphor of servant is used, it is speaking of Israel. You will find that Isaiah tells us that the servant is Israel several times.
Ancient Judaism believed that that prophecy was messianic. The Astonishing Servant of Jehovah
Now let me give you a little history. Ancient Jews interpreted this prophecy as messianic originally, okay? In all the ancient Jewish literature, this chapter, 53, this whole area, whole section, mid-section of the final 27, it was all messianic. All of it was messianic, though they were not clear on how the Messiah would suffer. When they came to chapter 53, they wrote this, the rabbis wrote this, “That He will be compassionate, that He will sympathetically feel our pain,” and that’s as far as they would go.
They understood that He would be a sympathetic Messiah, that He would be a righteous King, put another way, who felt so sorry that such a noble people had suffered so greatly that He felt their pain. They saw no messianic substitutionary death in spite of the fact that every day of their history animals were dying, portraying substitutionary death. All they saw in their writing was sympathy, sympathy. This messianic view of this section, by the way, shows up in the Jewish liturgy for the Day of Atonement.