This past Shabbat a former student from KSDS asked me the following:
Question: Why do we repeat the amida?
Answer: Because the Rabbis knew that not all worshippers were able to read, so they devised a way that one can still participate by saying amen.
Really interesting follow up Question: Why is it the prayer leader who has to fulfill that role? Couldn’t the community (the other worshippers) fulfill the obligation for those who can not read?
Best stab at an Answer: It hinges on kavannah (personal intention in prayer) and the prayer leader prays with the intention of helping others fulfill their obligation. Individual davenners do not necessarily have that kavannah.
In your second question it sounds like you are imagining a hevruta style prayer experience which is very intriguing but wreaks havoc with the traditional notions of minyan and shaliach tzibbur (prayer leader). Historically, I should also mention that the laws come from a time when there were fewer printed books, as well as less prayer literacy.
**Overall, her questions made me think about the interplay of the community and the individual. She also reinforced for me the hierarchical nature of public prayer. Any other responses you might suggest to her?