and watch all the chargeback scammers abuse that, and then after a while see bread/simplex remove that 'feature'.
haven't they realised the reasons most services don't offer credit card purchases. anyway goodluck to their profit/bottom line
This is only the matter of the margin per purchase, if they make the customers pay a margin that is high enough to cover the chargebacks (and not all of the credit card holders will start a chargeback after the purchase) they can make profit at the end. They can also ban their customers from paying with credit card after the first charegeback. Also, they can make a limit for the credit card purchases to maximize the possible loss of the chargebacks.
Of course, they can't apply a really high margin because in that case the price won't be acceptable for the customers, so it's not easy to plan and to calculate.