Why BNB works for hosting in Italy
BNB sits in the exchange wallet many buyers already use, so the transfer is a withdrawal rather than a purchase. In Italy the alternative is a card billed in dollars against a Euro (EUR) balance. A local card is normally billed in EUR, and whether a dollar invoice adds a conversion fee depends on the bank that issued it.
Paying from a wallet takes the bank out of the transaction. The invoice is priced in US dollars, the BNB amount is locked for 15 minutes at the live rate, and the transfer goes straight to the address on the invoice. Nothing to approve, no merchant category to argue about.