Why USDT works for hosting in New Zealand
USDT holds its dollar value, so the invoice never drifts between the quote and the transfer. In New Zealand the alternative is a card billed in dollars against a New Zealand dollar (NZD) balance. A local card is normally billed in NZD, 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 USDT 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.