In Sweden banks require you to have the BankID authentication app to login on web page (and banking apps, and many other pages).

Banks may offer a physical device but that's another device you have to being with you, and it's not supported by all services anyway.

While not required the same way as water or air is required, it's super limiting and inconvenient to live in Sweden and not have access to the BankID app (either on Android or iOS).