However, this isn't just the FDA.
If $DISEASE kills 10k people/year, the company manufacturing the device doesn't have to pay anything for them.
If $DEVICE kills one child, the company manufacturing the device is on the hook for several million dollars.
So your $DEVICE needs to clear (roughly) 10K*5%*$2 million per person killed or roughly $1 billion in profit to be economically feasible.
That means that those 10k people need to spend, $100K+ each for that device to make it feasible.
It's not just the FDA that makes companies want to drive that 5% down to damn near zero.