I get the benefit for the merchant to use an instant payment system. On the other hand, I don't understand the benefit is for the consumer. An increasing number of UK merchants use Pay By Bank (which is essentially an easy way to make a payment by pre-filling the merchant's bank details in your banking app), but if you choose to use it you're instantly losing the consumer protections that come from using a debit or (especially) a credit card: https://www.moneysavingexpert.com/banking/pay-by-bank-warnin...

The only way I would use such a system for purchases would be if the merchant refused debit/credit cards, and even then only if there wasn't an alternative merchant I could use.