the same logic applies for new planes. Why should I be obligated to implement this new safety feature when I have build the ones before without it? The MAXes w

the same logic applies for new planes. Why should I be obligated to implement this new safety feature when I have build the ones before without it? The MAXes where built after the regulation came into place therefore you better build it in. The same way you can't sell a new car without safety belts.