The revelation lasted 23 years.
Why were the Qur'anic verses not revealed all at once, but revealed in stages?
Why was the Qur'an not sent immediately as a complete book, but was it sent gradually over time?
Allah (swt) revealed the verses of the Qur'an gradually in proportion to the events and benefits, needs and situations of the people.
For example, alcoholic beverages were banned in four stages. Because alcohol has taken a very important place in the social life of the society in which the Koran was first revealed. Through the progressive ban, it has become easier for people to embrace change and abandon their lifestyle; their bad habits and addictions to which they were strongly attached with their customs for many years, perhaps centuries.
Another wisdom of progressive revelation was to place the verses in the memory of the Blessed Prophet Muhammad (pbuh) in the strongest and strongest way, so that He would transmit the verses to the people most authentically and correctly; as He always has.
What I Learned by Converting from Christianity to Islam | Zan Christ | TEDxHamlineUniversityhttps://www.youtube.com/watch?v=X1yKKGchRcc