The worst mainstream example of this I know of is PayPal. Their entire business is predicated on steering you away from using your credit or debit card (better for you) to a direct bank withdrawal (better for them). Bank withdrawals carry a risk of overdraft fees, have fewer consumer protections, and lack the rewards programs and other benefits of cards. But they cost less for PayPal. Merchants don't pay any less tho…
I'm no fan of PayPal, but I interpret this as a reflection of the state of the banking industry rather than scummy behavior on PayPal's part. Cards skim a ton off the top and are generally designed to gouge the merchant (i.e. PayPal) so customers remain blissfully unaware and keep using them; banks aren't making much effort to compete with direct transfers, probably because they get kickbacks from debit card use.
It's literally a case of using UI to steer customers towards a method that's worse for customers and no better for merchants.