Why can’t all cell providers have an agreement where if the user dials 911 or whatever the equivalent is in their country your phone will connect to any network if your provider isn’t currently available and route the call.
Being restricted to only your network when another provider might have a cell tower nearby with full signal is ridiculous in an emergency.
As I understand it...That's exactly how mobile phones work when you dial emergency number. if your operator has no signal, it automatically selects the strongest cell signal and attempts it through that. And you don't even have to know the country equivalent number, dialing 911 will automatically route to the local emergency center. There's a list of numbers that are recognized as emergency numbers by the phone/sim, but the actual number is not even used when the call is initiated. In general as long as you have a phone with battery left, you should be able to make a call to emergency center.