Salam
The Prophets in the past came as groups. They came to prepare the world for Mohammad.
People rejected them because they disliked the Authority the Prophets were given, which was all paving way for humanity one last Messenger.
Their chosen companions in ascension and glorifying and reminding of God were termed "family" in sense others were not, and they were the household, "people of the house" or "the family of the reminder".
The number of successors to the founding Messengers were Twelve Navigating Witnesses who were the True Leaders and Kings of their time.
In the past, because revelation didn't come to the end, there was wisdom to making these Prophets. And as the past, very few times was it that there was no people in need of conveying of the clear proof through a revelation and clarification from a Messenger, most of these Prophets were Messengers.
The recitations were not guaranteed to be safeguarded in the past although God if he wanted to, could have forced the issue.
The final revelation came in a dark time in the world, in a time after failure of humanity to receive the revelations, guard them or support the Messengers.
But never the less, despite Iblis delaying and delaying, Bani-Israel failing their mission, and Mohammad being foretold by Moses and the Twelve Successors of Moses, there was no going back.
And there was good prophecies for bani-Israel and there was dark prophecies, the former would occur if they obeyed, the latter would occur if they disobeyed. And the latter came true and the promises came true.
The cycle of the night when the truth of God's authority is veiled is something we all have to acknowledge or there would be no Messengers in the first place. Messengers came to establish and manifest and convey the truth of God's Authority and Command which is manifest and hidden, witnessed and unseen.
The night whence the truth is hidden and must be searched for and the dark veils of sorcery is cast upon the people but must be defeated is a hard trial indeed, and although humans can always make it out, it is as Quran says "where it not the mercy and grace of God upon you, you would of followed the Rebellious one except a few".
It is always possible to connect to the light and balance, without a recitation from God, but not much people would do it. Quran is a mercy in this regards, for it teaches the way to think and unlock the locks that close the doors to insight and reflection.
It also is continuous in revealing knowledge, it has all things pertaining to guiding humans, but most people understimate this because they think it's like a normal book.
It's a rope from God by which the leader and guide can manifest wonders is a connect from lowest earth to highest sky (Mohammad).
The sayings and ahadith of the Mohammad, Ali, and the successors all the way to Hassan Al-Askari, has a wisdom.
The waiting period for Imam Mahdi has a wisdom.
The wisdom is in Quran.
Moses, when he was sent, felt a constriction on his heart, the same constriction that Mohammad was told God knows his breast is constricted by what people were saying, and it is not due to a fault.
And God emphasized it was through Aaron that this occured with Moses, and that Moses affair was made easy through Aaron. Look at the prayer.
This emphasized on the need of Ali. Aaron and Ali and the covenant of Mount Sinai, represents succession, continuation of the Manifest Authority the founders were given.
When humanity rebells against this, and when their hearts turn away from the chosen ones and when they seek to oppress believers and kill those who command to justice and kill the chosen leaders of guidance, mainly the Prophets in the past, and the family of Mohammad pertaining to the end of revelations, they do so because they give rule to their enemies, denied knowledge of the book, and equate in religious authority the choice of people and mix in attributing purity to people through no proofs with those people who are given clear proof regarding their purity and chosen position to guide and leader humanity.
The elaboration of Quran is clear. Yes it could have been clearer, but is is clear. And it is a written in a way to teach us to reflect so that all humans see the clear religion of truth.
It is not simply here to appease Sunnis, who won't even accept what it clearly says regarding Wudoo so let us not expect us them to accept what condemns them and breaks their idols and manifest their polytheistic darkness.