looks like rendering adblockers extensions obsolete with manifest-v3 was not enough so now they try to implement DRM into the browser giving the ability to any website to refuse traffic to you if you don't run a complaint browser ( cough...firefox )
here is an article in hacker news since i'm sure they can explain this to you better than i.
and also some github docs
I notice the big American banks' apps don't care, as long as a compatible implementation of Google Play Services is available. Nor does my American bank seem to care that I do my desktop banking in Firefox on Linux. Is this an issue only in specific countries?
I'm afraid I don't know what you're talking about here. I don't have to give any kind of confirmation to make a transaction. What's a “tan app”?
I'm using a SailfishOS (Linux) phone and on SFOS forums it's one of the biggest complaints, they can't use their bank through the Android compatibility layer because it doesn't pass SafetyNet. I'm lucky enough that my bank doesn't do this, but I had to fiddle with low level stuff for Revolut to work - they require you install the app from Play Store or the app doesn't work.
Can you take your business elsewhere, to a company that doesn't require you to compromise your security and privacy?
If I didn't find a solution, I would, though it would be a great pain to migrate all my money spending flows.