What is the ruling on regularly (collectively) reciting "Subhana Rabbika Rabbil-Izzati Amma Yasifun, Wa Salamun Alal-Mursalin, Wal-Hamdu Lillahi Rabbil-Alamin" after every obligatory prayer?

Group dhikr (remembrance of Allah) after prayer is not from the Sunnah; rather, it is closer to bid'ah (innovation), whether it is by sending blessings upon the Prophet (peace be upon him), or by glorifying and praising Allah, or by supplication. It has not been established from the Prophet (peace be upon him) nor from his noble Companions that they committed to sending blessings upon the Prophet (peace be upon him) after every obligatory prayer, or to collectively saying, "Subhana Rabbika Rabbil-Izzati amma yasifun" (Exalted is your Lord, the Lord of Might, above what they describe). Furthermore, group dhikr in one voice was not done by the Messenger of Allah (peace be upon him) nor his Companions; rather, they prohibited raising the voice in supplication and warned that eagerness for innovation could lead to abandoning established Sunnahs.