Why does this call the problem by it's name, monopoly.
Android is another area Google are abusing their monopoly. Sure the phone market is a duopoly, but that doesn't help. Apple is even more locked down and user abusing.
Lots of app companies, like bank apps, think locking their apps to only work on official Android is best for security, but that compounds the monopoly. It's also arguably less secure!
I don't even understand. Am I getting this wrong?? Does the payment processing happen inside the banking app?! Because if so, that's the bigger problem isn't it? All the checks for correctness should happen on the servers that the banking app connects to, not the banking app itself. If that's already the case, then what are they worried about? I'm probably missing something here, but honestly I just don't understand why they would do that.
The app will almost certainly mostly be just wrapping a web interface. But this dedicated browser can provide the site with all the access of an app. The idea will be only this browser can be trusted to access this site and can check the run environment before connects. I'm they'd do the same on the desktop, if they thought it would be swallowed.