Why is it not possible to pay in advance or last name at Amazon?

I was lucky to be able to order a Ps5 but they canceled it because direct debit didn't work

Ask at Amazon! By the way, you can't pay with your last name anywhere.

Because both are complex procedures that make automatic processing more difficult (and in the case of cash on delivery also cost high fees)

Because Amazon does not offer / does not want to offer this payment method.

Amazon wants it to be easier. Above all, so many orders arrive there every day that they do not have to rely on prepayment or cash on delivery.