It's already reality in my country, where you cannot access online banking for any banks except via their mobile applications, which (of course) refuse to work on anything rooted or running non-stock firmware.

So, I guess it’s a country-dependent jump to conclusions?

I have had a lot of banks and credit cards, mobile payment apps like Venmo/PayPal in the US and they almost all work on mobile web and desktops.

But I recognize that wealthy western countries didn’t really skip the personal computer like many mobile-first regions have done.