I've intentionally used irreversible crypto payments to a merchant that is an an industry with high chargebacks. It is highly useful in transactions where the merchant is highly trusted but the buyers tend to be weasels. Such merchants tend to charge high premiums for reversible payment methods.

In such cases it is win-win for both the merchant and customer, the customer doesn't have to foot the reversibility overhead and the merchant is able to offer goods at the same profit margins but lower price which should yield more sales.