What is the difference between communal blessings (like Kiddush and Havdalah) and prayer in terms of proxy fulfillment?

Synopsis

Blessings such as Kiddush and Havdalah can be fulfilled by proxy for others, but personal prayer cannot, because blessings are communal acts performed with specific recitations, while prayer is devotional.

Late Acharonim
Lenient
Strict
Lesser cited
Major authority

Discussion

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