For me, if my phone still made phone calls, still sent texts, still got critical security updates, but I were forced to get Firefox from the app store to browse

For me, if my phone still made phone calls, still sent texts, still got critical security updates, but I were forced to get Firefox from the app store to browse the modern TLS 1.2 web, I would consider it still quite usable. For the average user who doesn’t know about security, having their phone updated w.r.t. security but having the phone’s built in browser break because it doesn’t work with modern TLS websites would be much better than having them have their phone compromised and critical information given to hackers. They would be able to get a new phone (or download another browser) if they want a modern browser with modern TLS; that’s a very different rodeo than the current situation of “update your phone or have security problems” with phones not even five years old.