require a separate device that looks like a calculator to use online banking

To be fair this actually provides a very high level of security? At least in my experience with AIB (in Ireland) you needed to enter the amount of the transactions and some other core details (maybe part of the recipient’s account number? can’t quite recall). Then you entered your PIN. This signed the transaction which provides very strong verification that you (via the PIN) authorize the specific transaction via a trusted device that is very unlikely to be compromised (unless you give someone physical access to it).

It is obviously quite inconvenient. But provides a huge level of security. Unlike this Safety Net crap which is currently quite easy to bypass.

which is supposed to enforce to run apps in secured phones

The point of the Google Play Integrity API is to ensure that the user is not in control of their phone, but that one of a small number of megacorps are in control.

Can the user pull their data out of apps? Not acceptable. Can the user access the app file itself? Not acceptable. Can the user modify apps? Not acceptable.

Basically it ensures that the user has no control over their own computing.