Actually the Quran in its entirety was memorised by heart by many people during the life of the Prophet itself. And it was written down in various parts during his life too.
In Abu Bakr'rs (RA) time, the first caliph and just a a year or two years after his death of the Prophet PBUH. It was compiled into one book by Zaid bin Thabit who himself was a Hafiz - a person who completely memorises the Quran.
This copy was kept with Abu Bakr and then Umar. Finally in the time of the third caliph Uthaman (RA), the single copy was copied again and sent to other parts of the world who needed a source copy. From which later more copies were made locally. This was only 24 years after the Prophets death. So to say it was written 140 years after for the first time is a misconception.
Infact, even the vowelisation, which was basically marks to help non Arabic speakers to correct their pronunciation was applied in the time of Muwaviyah (RA) which is pretty much exactly what we have today. And this was done within 50-60 years after the death of the Prophet.
HISTORY OF THE QURAN COMPILATION
But the point is not this here, its completely different, some people are confusing the issue and not responding. No one is able to point to any prominent Islamic scholar advocating their point of view or a verse from the Quran for the same and all they can do is deviate the topic. Others are bringing in Muslim civilizations like the Ottomans or Ummayads and what not which on their own were very advanced for their time and made significant contributions towards the science and technology. But were they theocracies? Did they come about by a "revolution" where clerics became the head of state? They did not.
Don't fall for the deviation tactic. Keep on track on what the topic is like a laser focus.