It seems that H-shem is only "blessed" when there is a communal declaration of His greatness. The person that says the bracha is only "serving up" the opportunity for the kehila to do the gmar mitzvah with a thunderous amein. (This is how I'm understanding the tshuvas harashba 5:53)
So, I can understand why at the completion of all the middle brachos, the amein at the end is as important as "yehei shmei rabbah" etc. because the community is declaring that Hash-m is the source of all the brachos that we need.
However, why is the amein at the end of hakeil hakadosh more important? Is it because it counts as another kedusha when the whole tzibbur says amein to that bracha? If not, is it because it's the conclusion of the brach(os) of the first section? If that is true, so why doesn't the amein at the end of sim shalom get the same status?
Avraham Halpern, Flushing
Shalom Avraham,
Thank you for the excellent question.
Before addressing the Gemara itself, it may be worth slightly refining the assumption based on the Rashba. The Gemara in Berachos 45b discusses whether a person should answer Amen to his own Berachos. The Rosh (Berachos 7:10), Talmidei Rabeinu Yonah, and the Rambam (Hilchos Berachos 1:16-18) explain that answering Amen at the conclusion of a series of Berachos serves as a declaration that one has completed that unit of praise or prayer. Thus, Amen is not merely the congregation's response to a Berachah. In some cases, a person says Amen to his own Berachah. It functions as an affirmation and conclusion of a completed section of prayer.
Furthermore, Amen has significance even when no one is being Motzi anyone else. A person who is not fulfilling an obligation through another's Berachah still answers Amen. This suggests that Amen is not merely a mechanism of Yotzei, but an independent expression of affirmation and acceptance of what has been said.
In light of this, the Rashba may not mean that the Chazan is merely "serving up" an opportunity for the congregation to complete the Mitzvah. Rather, Amen appears to add an additional layer of affirmation and confirmation to a Berachah.
Turning to your question, we find that the Yerushalmi (Berachos 4:6) assigns special significance specifically to Amen after "ha'Kel ha'Kadosh" and "Shome'a Tefilah." The Mahari'a, cited by the Beis Yosef (Orach Chaim 66), explains that Amen after "ha'Kel ha'Kadosh" is important because it concludes the first section of Shemoneh Esreh, the section of praise. Amen after "Shome'a Tefilah" is important not only because it concludes the middle blessings, but also because "Shome'a Tefilah" serves as a comprehensive Berachah encompassing all requests. Thus, according to the Mahari'a, "Shome'a Tefilah" possesses an added significance beyond merely marking the end of a section.
This brings us directly to your question about "Sim Shalom."
Some Acharonim explain that it was not singled out because the individual will shortly reach that Berachah himself and answer Amen there after his own Berachah, according to the Sefardi Minhag. In other words, the omission does not necessarily imply that Amen after "Sim Shalom" is less significant. Rather, there is less need to interrupt now in order to answer the Chazan's Amen when the individual will soon arrive at that same point in his own Shemoneh Esreh.
Incidentally, according to the Beis Yosef who says one answers Amen after his own Sim Shalom, much of this discussion is theoretical, since he rules that one does not interrupt during Keri'as Shema and its Berachos even for these Amens. Nevertheless, the underlying explanation remains important, because it suggests that the omission of "Sim Shalom" is practical rather than conceptual.
The Magen Avraham (OC 66:7), however, cites the Levush who suggests that according to Ashkenazic practice, where one does not answer Amen after his own concluding Berachah of Shemoneh Esreh, there is indeed room to interrupt even for Amen after "Sim Shalom." According to this approach, Amen after "Sim Shalom" truly shares the same status as the Amens after "ha'Kel ha'Kadosh" and "Shome'a Tefilah," since it marks the conclusion of the final section of the Amidah.
However, the Magen Avraham brings the Divrei Chamudos who disagrees in practice, but not in principle. He likewise recognizes the importance of the conclusion of the prayer. His argument is that this role is already fulfilled by the Amen recited after "Oseh Shalom" at the conclusion of Elokai Netzor, and therefore there is no need for an additional interruption specifically for Amen after "Sim Shalom."
In summary, the discussion in the Poskim does not necessarily treat Amen after "Sim Shalom" as less significant. On the contrary, some understand that its omission is practical rather than conceptual, while others, such as the Levush cited by the Magen Avraham, explicitly argue that it should receive similar treatment. According to that approach, your intuition is essentially correct: if Amen after "ha'Kel ha'Kadosh" and "Shome'a Tefilah" derives its importance from concluding major sections of the prayer, there is good reason to view Amen after "Sim Shalom" in a similar light.
I hope this helps.
Kol Tuv,
Aharon Steiner