>Or maybe an approach which is on a spectrum between >increasingly onerous not to own one at all.

Yes, and I think this unfortunately demands a grey area. I'm starting to treat my smartphone more like a work device, and there are a few things I do on it:

- My work's authenticator app is there.

- Unfortunately Signal is tied to smartphone usage.

- Practically speaking, people will expect to be able to send you text messages.

- It's still useful for taking pictures.

- My banking app is on there.

Outside of rare occasions, that's really all I use my phone for. I don't carry it around the house. If I go somewhere with my wife, I don't even bring my phone most of the time. I'm "required" to have it, but in principle it's not even mine. It shouldn't be trusted or enjoyed.