Yea, interesting, this is where we are.
But pushing this absurdity a bit further, what exactly makes it a voice call instead of a text chat? Either way, there are bits moving over wires.
Let's make a new "voice codec" that can trivially encode and decode to text (like Speak'n'spell phonemes) so that the bits on the wire technically represent some "audio data", but with much less overhead than the usual TTS.