Your point of #3 is probably wrong. It’s harder to get fossils of aquatic creatures so there’s likely a vast number of animals that we will never know about. Sa

Your point of #3 is probably wrong. It’s harder to get fossils of aquatic creatures so there’s likely a vast number of animals that we will never know about. Saying with certainty that the biggest aquatic reptiles were smaller than whales is a logical fallacy. Only the ones we know about are smaller but we don’t know if there ever were, we might get lucky and find a fossil that is larger.