Worse yet, you could talk at the same time as the other person! Carrying on a conversation with my mom is like talking at that fancy riot mike from a few years ago [0]. If you don't have a perfectly negotiated rhythm, you're gonna talk over the other person, cutting them off, missing part of their sentence, and then begin a flood of repeat/acks before starting again. It's bloody idiotic, and my mom is convinced she's just terrible at talking to people, when instead for the first time in her life the phone is too dumb to do the job right; she thinks she's terrible with tech, and it's really just dumb machines failing her expectations.

And never mind the loss of fidelity so you can't tell someone's tone or not.

Almost makes me wanna just chuck this miracle slab of supercomputing glass. plonk

[0] Seems like it's called the Delayed Auditory Feedback effect. Some researchers built a directional mike/megaphone combo that basically stupefies anyone it's pointed at into silence.