Parmandur
Book-Friend, he/him
But why? CoC is the BRP system with sanity and mythos monsters... why is it a better system than 5e using sanity from the DMG and creatures from the Far Realm for simulating an investigative Cthulhu story?
EDIT: And do those advantages offset cost in money, time, brainspace, familiarity, etc.?
EDIT 2: It's interesting you brought up this example as I am currently running this type of adventure to kick off a plane exploration campaign in my current game.
Not to mention, Sandy Peterson who created CoC, has made a 5E Cthulu Mythos supplement.