Magic Resist items buff pls

I'm just tired to get demolished every game by high ranged midlane mages/ap "supports" Current "classic" mages are frustrating as well. Seriously they force me to build 200+ magic resist and even this isn't enough to absorb at least 50% of incoming damage (Seriously WTF it gives total % magic resist shred unlike bonus armor penetration LW for adcs.). The worst part why would I buy like 180-200 (min 2 slots) magic resist just because they picked 1 mage guy? When they have on their team . After CotC nerf I have no idea how am I going to survive against this absurd. Upvote for the love of