The people who are in a position to do this are probably in a position to do anything else they want to do with said phone calls. What's changing is that random joes can do this stuff now.
No, modern AI tools make dragnet surveillance much easier. Imagine that the State bans a certain religion, and has the ability to automatically detect apostatic or heretical speech in private conversations without a tap, without an agent reviewing the recording, and with a fraction of the compute needed in the past
No, I'm not really worried about Joe doing that, just Uncle Sam
Google does this quite efficiently. I am confident that everything going over Voice service (and probably Fi as well) is transcribed in real-time and dumped to the correct agencies.
I can reliably trigger a disconnect for my calls if I blurt out a series of keywords. Distinct behavior from my mobile carrier's neutrality.
Think of a tool that you can say "Listen to all phone conversations and notify when someone talks about $TOPIC"