Why are Medieval-era middle eastern/indian weapons stereotypically curved (scimitars and sabres). Is this because they used these weapons more in history or is it something the media latched onto (like horned viking helmets)? If its an accurate stereotype, is this because Middle-Eastern and Indian societies used less metal armour than European ones?
It's an inaccurate stereotype (early Medieval Middle-Eastern and Indian swords were typically straight). It started to become accurate in the late Medieval era (when curved swords started to be used in those regions), and eventually became accurate (when the curved sword become the common sword in those regions (and also in Europe)). But it isn't just modern media; it's an old stereotype - there is Medieval European art showing Saracens with curved swords fighting Crusaders with straight swords (but the Saracens are shown with European curved swords!).
A few months ago, we discussed the question of straight vs curved swords in East vs West, both the swords that were actually used, and stereotypical depictions in European art: https://www.reddit.com/r/AskHistorians/comments/86it3s/why_did_eastern_armies_prefer_curved_swords_over/