"You'd have a comfortable retirement" implies stock returns are knowable, which they are not. And the people assuming forward returns will be like past returns

"You'd have a comfortable retirement" implies stock returns are knowable, which they are not. And the people assuming forward returns will be like past returns seem to be the least knowledgeable on evaluating assets. 12,000 a year is a lot less per year if you are saving for your child's college education.