Insurance like that is normally because if the potential size of the loss. Losing a house is way more than most people could stand. A closer example might be buying the extra service contract on every electronics purchase you make: that's usually a bad deal.
> But it’s still worth the extra cost for most people.
Is it? You charge back over 2% of your transaction volume? If you don't then just removing the middleman will make everyone happier. If you do, I have questions as to why...