The sheer volume of communication data is far too large to monitor everything.

By people, sure. Run it through a magical analytical algorithm that flags stuff for people to look? Or if that’s still too much everywhere, they could focus it on a certain area’s towers and process that data. Will it catch everything or not generate false positives? No, it’s not perfect, but I could see it helping them and being done.

I doubt an agency like this would just hoard the info and not proactively use.

Even a lot of offices have moved to VoIP.

I would like something in between…BTW I’m installing Bazzyte on another PC.

If you’re somewhat familiar with uBlue, Bazzite, and immutables, I’d go with Bluefin (Gnome) or Aurora (KDE). All three are uBlue / based off Fedora, so you don’t have to learn a 2nd OS while working on your current OS (Bazzite).

https://universal-blue.org/