Well, to me it is pretty plain that Isaiah 53 is NOT speaking about the nation of Israel, for these reasons:
1) Isaiah writes about his nation (Israel) holding the suffering servant "as of no account,"
So Israel holds Israel as of no account. What's the problem with that?
and "Jehovah himself has caused the error of US ALL to meet up with that one," and "because of the transgression of MY PEOPLE he had the stroke." How could Isaiah be referring to the nation of Israel---his people---when it is they who held the suffering servant as of no account, and it is they who transgressed and therefore had to find a reprieve in the suffering servant?
Since when, when A sins, does B gets punished for it??
It is very simple: When Israel sins, then Israel gets punished. That concept you see all over the Tanach.
The concept that when Israel sins God Himself has to be murdered by His creatures before He can forgive them, is
NOWHERE to be found in the Tanach.
When the Jews sin, the Jews gets punished, and through the punishment the sin is erased.
2) Isaiah writes that this suffering servant "had done no violence, and there was nodeception in his mouth." (verse 9) Such was not the case with the nation of Israel. Sad to say, they had a history of violence and deception. It's not pleasant to relay this information, but it stands as truth, because it is recorded in the very Tanakh of the Hebrew scholars.
It doesn't speak about the whole history of the Jews, but about a timeperiod in which they didn't do violence or deceit.
But they did do idolatry, and for that they got punished.
"The remnant of Israel shall do no unrighteousness
And speak no lies,
Nor shall a deceitful tongue be found in their mouth;"
Zephaniah 3:13
So, as I see it, the nation itself cannot be the one that Isaiah 53 speaks about. It says that this one that comes to take on himself their errors is someone other than the nation itself. He "will bring a righteous standing to many people," and "he will carry the very sin of many people." (vs.11,12) How could the nation of Israel do that? It itself was in need of help. How could it help Isaiah's people when it WAS Isaiah's people? How could the nation sacrifice itself for itself, when it was steeped in violence and deceit?
How could it not? When somebody sins, that person gets punished. Sometimes with death. In that case he makes himself an offering for (his own) sin.
Isaiah uses poetic language. In one sentence he addresses Israel directly as "they" or "we", and also through the metaphor "the servant".
That may give the impression that he is speaking about different subjects, but that is not the case.
He is just no so very exact with pronouns, as we can see in for instance Isaiah 42.
Nobody in his right mind will deny that Isaiah 42 speaks about Israel, and that the servant there is Israel, because that is plainly mentioned several times in the text.
However, Isaiah addresses that servant with different pronouns, even in the same sentence:
"Who gave Jacob for a spoil, and Israel to the robbers? Did not the LORD, he against whom
we have sinned? For
they would not walk in his ways, neither were
they obedient unto his law. Therefore He hath poured upon
him the fury of his anger, and the strength of battle: and it hath set
him on fire round about, yet
he knew not; and it burned
him, yet
he laid it not to heart."
We see here that Isaiah, clearly speaking about the Jewish people, jumps in this short piece of text from "we" to "they" to "he". Three different incompatible pronouns, both singular and plural, all for the Jewish people.
That doesn't mean we're dealing here with three different subjects, that's just the writing style of Isaiah, and the same goes for Isaiah 53.