Who could imagine that people would install telescreens voluntarily, and pay for the privilege?
https://i.pinimg.com/originals/70/bc/c9/70bcc9ab4c2ab6e22e29...
You're technically correct that cell phones leak all sorts of meta data that can be used for surveillance, but they aren't always listening. Voice assistants, however, are designed to be always-on and that is the key difference.
Some phones aren’t designed to always listen, but voice assistants aren’t designed to record everything and upload it, so what’s the difference? In both cases, you’d need something that goes beyond the advertised functionality.
However, Orwell's envisioned surveillance apparatus is ubiquitous all over the planet, no matter what nation you live in.