When you spend $100,000,000 on your offense and only $36,000,000 on defense your offense should be expected to win games. That is what we are spending on both sides of the ball this year. You can't have the same expectations for the defense as you do for the offense when you are spending slightly more than 1/3 the money on it.
The real question you should be asking is why are we spending 3 times as much money on the offense for them to only score 17 points?
The chiefs, since you brought them up, are spending $52M on offense this year or almost 50% more than we are.
https://overthecap.com/positional-spending/