I kinda agree with the big bait theory although I've caught lots of fish like blue marlin on small
feathers and albacore on a bare #6 hook. The reason for big baits is to discourage smaller fish from trying to take them thus giving more exposure time for really big fish to have a good meal. Also, most of us anglers have probably come across big floaters with huge fish caught in their mouths that they can't swallow. Big appetites can get fish in trouble eating big prey but overall I'd say that's an exception to the rule. All I know is that when we want really big roosters, etc. we use big baits like live black skipjack to increase our chances. When those baits are taken you just know it's something big.