There's also an important point about enforcement. In California literally all sex that all under 18s have is illegal and has been for 100 years. but only about half of Californians are virgins when they turn 18. That is a LOT of illegal sex which is never prosecuted. One could argue that the law doesn't need to be changed, we should just completely ignore it as we've been doing, while we work on getting people to accept the fact that teens can have happy healthy sex lives and no one need to have hysterical meltdowns when somebody has an older partner.
