[Dobbs]

Being able to call 911 is an essential part of a phone. To the point that Apple (and I'm assuming Google) both allow calling emergency services while the phone is locked.

[ben-schaaf]

In lots of countries it's also possible to call emergency numbers without a sim card.

[mig39]

When you take the SIM out of an iPhone (or turn off your eSIM), it displays “SOS” instead of a carrier ID.

[numpad0]

Yes, because 3GPP defines requisite emergency call flow, and FCC require phones able to make emergency calls without SIM. It's not a gesture of generosity.

[kwhitefoot]

It's not just possible, it is a feature of the GSM system. As far as I know it is a requirement in Europe.