Why has prayer not been detailed in the Holy Quran as thoroughly as Zakat, fasting, and Hajj?

Allah Almighty has profound wisdom in His legislations; He may reveal some of it to people and conceal other parts as a test for them. Prayer, like other acts of worship, has some of its rulings clarified in the Quran, such as the Qibla and prayer times. The Sunnah completed the clarification of the remaining rulings and their details, because the Sunnah is revelation and a proof. Allah Almighty says: "Nor does he speak from [his own] inclination. It is not but a revelation revealed" (Quran 53:3-4) and "And We revealed to you the message that you may make clear to the people what was sent down to them" (Quran 16:44). Therefore, Allah has made obedience to the Messenger (peace and blessings be upon him) obligatory and considered it part of obedience to Him: "Whoever obeys the Messenger has obeyed Allah" (Quran 4:80).