The Muslim empire conquered a grand Christian civilization and coasted on their stolen prosperity until too many of their dhimis converted to the religion of death and stagnation. The Muslims raped, robbed, murdered and converted their productive captives to oblivion and then sank back into their original savagery and misery.
Islam always spreads from the blade of a sword, or the barrel of a gun. Nothing peaceful, productive, or joyous is ever the result of “accepting” it.