>I don't understand why voice calls aren't just a standard and required part of the 4g and 5g specifications??
They are, it's called VoLTE/VoNR. For whatever reason telcos add whitelist schemes to prevent phones from making voice calls, even if they actually support it.
One of the australian telco (Telstra) is shit - they have a custom VoLTE configuration which is often not preloaded into a grey import phone. An example would be the older xiaomi phones. These phones will not be able to make VoLTE calls on the telstra network, if they're using the optus network (which is the other telco).
Therefore, it is not compliant with the legislated requirement that all phones must be able to make emergency calls on any network. By blocking it, the telcos cover their ass, at the expense of the consumer having to upgrade - even if said phone was actually possible to make work with a bit of software tweaking/upgrading.
Not to mention that there's an alternative way to fix this problem - create an app to make emergency calls over data network, which would work in theory (it's only voip that isnt standardized). This is exactly what india did, with their Jio app.
They are, it's called VoLTE/VoNR. For whatever reason telcos add whitelist schemes to prevent phones from making voice calls, even if they actually support it.