How was Taksashila (where my cousins live today by the way) destroyed by Muslim invaders when it happened before Islam existed? Don’t you mean the Huns, as your own cited source of Britannica says? See my other comment in this thread.
>The White Huns and Alchon Huns swept over Gandhāra and Punjab around 470 CE, causing widespread devastation and destruction of Taxila's famous Buddhist monasteries and stupas, a blow from which the city would never recover. From 500 CE to 540 CE, the city languished [54] after falling under the control of the Hunnic Empire ruled by Mihirakula. A patron of Hindu Shaivism,[55] Mihirakula presided over some destruction of Buddhist sites and monasteries across northwestern regions of the Indian subcontinent.
cf. “Decline” in https://en.m.wikipedia.org/wiki/Taxila#History
>The White Huns and Alchon Huns swept over Gandhāra and Punjab around 470 CE, causing widespread devastation and destruction of Taxila's famous Buddhist monasteries and stupas, a blow from which the city would never recover. From 500 CE to 540 CE, the city languished [54] after falling under the control of the Hunnic Empire ruled by Mihirakula. A patron of Hindu Shaivism,[55] Mihirakula presided over some destruction of Buddhist sites and monasteries across northwestern regions of the Indian subcontinent.