There's a > 40 mile stretch of state route 542 (mt baker highway) in WA where there is no cell signal. Zip. Nada. No matter the carrier. And this road can carry nasty rapidly changing weather conditions in the winter. Your iPhone 26 will continue to proudly display "No Service." So, no, it has not replaced this.
No, I don't think $200 phones are getting satellite connectivity.
T-mobile's service will be limited to various forms of texting and possibly also Twitter, which is used by many emergency departments to broadcast information, which is slightly different than the iPhone's offering of dire emergency service coverage. Still doesn't replace AM radio use cases though.
https://www.t-mobile.com/news/un-carrier/t-mobile-takes-cove...
There is no cell phone signal in many areas.
'Can' is putting in a lot of work, there.
Google insisted on showing roads continuing to be closed well after e.g. CalTrans issued a statement otherwise and reopened them, after the last bout of winter storms in early March.
The response time to displaying or ending closures related to wrecks on less well traveled roads is abysmal as well.