Why do we perform Tarawih prayers, and why do the Shiites not perform them?

The people of Sunnah and Jama'ah perform the Tarawih prayer, following the Prophet, peace and blessings be upon him, in his sayings and actions. He encouraged performing qiyam in Ramadan and led it in congregation for several nights before discontinuing it, fearing it might become obligatory for the Ummah. After his passing, peace and blessings be upon him, and with the removal of the concern about it becoming obligatory, the Companions unanimously agreed upon it with the approval of Umar, may Allah be pleased with him, considering it a good Sunnah. As for the Shia, they consider it an innovation due to their animosity towards Umar, may Allah be pleased with him, and their fabrication of false narrations attributed to the Messenger and the Ahl al-Bayt prohibiting Tarawih. This contradicts the consensus of the Companions and the established Sunnah.