One phone for banking and another one for browsing.

This is what will happen sooner or later. One cheap, non-rooted, Googled Android phone at home for 2FA and other official nonsense, powered off when not in use.

All other business, including personal communications, conducted on a GrapheneOS device. These days you don't even need a phone number for your everyday device, a data-only roaming plan like silent.link is enough. This is not yet necessary in the U.S., but we are dangerously close.

Easier said than done. You have to maintain two phones then (updates, keeping charged). You don't want to carry two phones around. Also you have to have two SIM cards/telephone numbers which costs money.

You jest, but an actual "digital wallet" device is something I'd quite like to see. Something that's actually secure (like not running an ancient android version that never sees security updates). That only deals with money, without any garbage running on it. That displays and verifies the amount before processing any contactless payments. That supports multiple banks, multiple bank accounts, multiple payment cards etc.

I utterly detest the idea of having to use a phone for anything that I'd like to be secure. I browse Reddig on that thing. I watch porn on that thing, I don't want my porn anywhere near my bank account.

In this economy? /s

The other more compelling reason why people would have a rooted phone is to run ROMs that may still be providing OS support where the stock OS has been abandoned or EOL'd by the developer.

Having an unlocked bootloader at the minimum would be required in those scenarios. It actually saves hardware that still works from ending up in landfills.

edit: spelling