UBS Switzerland has a decent system. When I first opened the account 15 years ago we had a number pad of codes on paper we entered as the authentication. Then later we got a credit card sized electronic device where we enter a passcode and it gives us a one-time code to enter to login. And now we have an Access app - we go to the website, enter our contract number, point our phone at a QR code on the webpage and authenticate on the app, and the desktop browser logs us in. The access app also is used for logging in with the mobile banking app. It never relied on sms.
Super simple but probably costs some money to develop.
Super simple but probably costs some money to develop.