They conquered then took credit for everything. That’s it. They were never “great” at anything but war, murder, and subjugation.
Bingo.
The dark age of Europe happened when Islam cut it off from various trade routes and put them under constant siege.
Correct.
It is not difficult to determine. Just follow history beginning with Muhhammad and the three Mecan Wars. From that point on it was about stealing from others and forcing others to become Muslims.
Now just fast forward to Islam today and ask what great leaps has Islamic nations make today? The damn rag heads wouldn't even know about oil or how to drill for oil if the Americans, Brits and Dutch didn't teach them. 95% of Muslims in the world live in abject poverty today. That is the height of Islamic civilization.
And, let's not forget their expertise at inbreeding.
Don’t forget camel humping and pedophilia.
Not quite. They conquered, assembled the disparate knowledge from Greco-Roman and Hindu civilizations, made some advances which were obvious once you had both (like algebra, which is dead easy to develop once the Hindu notion of zero is applied to Diophantine equations), had a brief period when they actually began doing empirical science, then threw it all away by replacing both the Islamic Aristotelianism of Avicenna and Averroes and empiricism with al-Ghazali's occasionalism, that allowed no room for natural laws, both vitiating the basis for science and giving an intellectual defense of the slothful fatalism that has ever since characterized Islamic endeavors in all things, save warfare.