Something like iDeal, which is a payment processing system in the Netherlands.
It works so well and is very secure. You get to the checkout page on a website, click a link. If you’re on your phone, it hotlinks to open your banking app. If you’re on desktop, it shows a QR code which does the same.
When your bank app opens, it says “would you like to make this €28 payment to Business X?” And you click either yes or no on the app. You never even need to enter a card in the website!
You can also send money to other people instantly the same way, so it’s perfect for something like buying a used item from someone else.
Plus the whole IBAN system which makes it all possible!