>>519229802
>they get to pillage everything they lay their sight on
Wrong. Most crusades were defensive campaigns to defend or retake Jerusalem. First Crusade saw the army marching through allied Byuantine land, then into Syria. Crusaders only began to plunder if resources ran low. Undisciplined plunderers like the people's crusade were simply killed en route.
>Muslim world was much richer than Europe at the time.
Also wrong. You can read about the history and economics of Europe from the Leonid Dynasty to the Great Schism. Or you can take the Gooner Degeneracy Product for 1000 AD.