This is due to their schooling which has deteriorated precipitately and their Paki minority. Tests showed that most students of the batch of 2003 couldn't pass the exams of the 1950s in Brit schools
But the world we inherited would not have come about without them, and would have been much poorer for it. -- that is true.
The "arabs" -- again, let's be specific and use this to refer to only the Nejd Arabis -- Mohammed and tribe
They didn't produce anything.
The Assyrians, Babylonians were Semites like Arabs or Jews but of different (Amorite or Akkadian) stock.
These Nejd Arabs didn't provide anything, BUT a continuous empire from India to Europe, which allowed for mixing of ideas on a scale that hadn't happened since the Seleucids (and was started by the Persians under Cyrus)
Although they officially want everybody to look to Mecca and Medina as the "source" the city state of Petra and the highlands in Yemen, devised a way to trade in the near abroad (to borrow a soviet term) and build stores of gold and silver.
Although the Silk Road was, so to speak, 'Down', their own overland trade route wasn't and what little trade came from the Indian ocean litoral or the Eastern Mediterranean, would go through there.
Their population centers were far enough removed from the areas affected by recurring plagues that they managed to miss out on that business as well.
One day the guys at Petra discovered the outside world and that changed everything for everybody. Discovery 2 was the Byzantine Army ~ they hadn't been paid in a century. It was a "Hello boys, you need jobs?" Moment.
After the lightning conquest of Syria the Arabs sat down and invented Mohammad and everything that went with it. They continued to buy Byzantine military strength and quite rapidly (as such things went in those days) drove the Persians back to the old Persian core.
That was quickly followed up with economic hegemony in North Africa and the Fertile Crescent ~ and virtually total neglect of the North shore of the Mediterranean.