The Muslim centers are not only preserving ancient Greek learning and books, they are cherishing and enriching them for several hundreds years [1]. To them these ancient Greek books are equivalent of modern days da Vinci's paintings that can be weight in gold, literally no kidding. At the time, if you are doing translation of any Greek texts you can get paid by the weight of the translation in gold equivalent! Please tell me at any other time this is happening in any part of human history or even now.
It's also reported that at one time, Abbasid Caliph Al-Ma'mun was demanding an original copy of the Ptolemy's Almagest book as the condition of a truce between Byzantine Empire and the Abbasid Empire. This is really something big because based on the saying of Muhammad that prophesizes any Muslim leader who can defeated and conquered Byzantine Empire (Constantinople) is the best leader ever. He basically abandoning this potential privilege title because of an original copy of Ptolemy's book. If you think he is too weak to defeat Byzantine and resorting to lame truce, please think again. He basically conquered and subjugated entire modern day Afghanistan for good, and only a few legendary leaders that even managed to do that including your beloved Alexander the Great. For the record, the mighty British Empire and USA did not manage to do just that.
Al-Ma'mun is also the founder of the "House of Wisdom" where Al-Khwarizmi was the first director of the center and his name is very familiar because apparently the "algebra" and "algorithm" words were derived from his book title and his names, respectively. Because of his contribution to science one crater in the moon (Almanon) is named after him[2].
Believe it or not, according to some of modern historians, the extreme love for knowledge of the Abbasid Empire was partly blamed on the downfall of the Abbasid Empire at the expense of Islamic spirituality. This perhaps mainly due to the Islamic teaching that says after you're dead there are only three things that can increase you deeds in the hereafter. Firstly your God fearing children, secondly your donated and lively wealth for charity (waqaf) and thirdly your contributions to the knowledge that are beneficial to other people.
[1]How Modern Science Came Into The World, https://www.jstor.org/stable/j.ctt45kddd