You are missing the opposite side of the fraud picture: Where it's not the business scamming you, but someone taking your credentials and spending up to the limit in a store that deals with no chargebacks. This is, if anything, the larger size of the fraud losses for the Stripes of the world. Fake businesses that use the cards either for testing if the creds are good, or where the owners charge cards that they obtained from some other malicious actor.

So it's not that I get 3% off by not supporting chargebacks, but whether I want to have a dollar under a payment system that supports someone emptying me out without recourse.... and the answer is often no.