Is the phrase "Allahumma salli 'ala Muhammad" (O Allah, send prayers upon Muhammad) sufficient to fulfill the command in the Noble Qur'anic verse: "Indeed, Allah and His angels send blessings upon the Prophet. O you who have believed, ask [Allah to confer] blessing upon him and ask [Allah to grant him] peace"?

Your assumption that the Muslims' request to Allah to send blessings upon His Prophet does not constitute compliance with the divine command is a false assumption. This is because the Prophet, peace and blessings be upon him, is the one who taught us how to send blessings upon him, as it is narrated in the Two Sahihs that the Companions asked him: "How should we send blessings upon you?" He said: "Say: 'O Allah, send blessings upon Muhammad and upon the family of Muhammad...'" Therefore, our request to Allah to send blessings upon His Prophet is a compliance with the method we were taught, an acknowledgment of our inability to fulfill his right, and a plea for Allah to grant him the worthy status he deserves.