Same.

> I check to see if my wife’s left work yet to know if I should start dinner

I (we) don't even do that, on purpose. If we want to know, we ask by message or call.

> The reason [...] leave it turned on is that we’ve never, not once, used it as a spy device.

I agree, it's all about trust. In my mind it's exactly like being a mail server sysadmin: by design you have access to all the emails but you never read them out of ethics. In that spirit: we have location-based automations set up in Home Assistant, and by default there's a geocoded location entity per tracked device, which I disabled, relying only on zone enter/leave events, carefully balancing privacy and convenience.

Now, the use case about leaving it on at all times is:

a) If you turn it off there's a chance you forget to turn it on. That's also why the new iOS check-in feature, while nice, doesn't cut it.

b) The most trivial reason: my wife frequently misplaces her phone (and other things, which recently got airtagged).

c) My wife works in a bar; let's not kid ourselves, the nightlife way back home carries additional risk: e.g bars close at about the same time, which generates a flux of drunk people in the streets, who are more prone to do dangerously idiotic or hostile things (from driving under influence to downright assault). While not frequent incidents are not unlikely either: over the course of two years there has been about a dozen, a few were life threatening; luckily she managed to either avoid, defuse, or escape such situations, but one day she might not and end up being unable to actively alert. Once while riding her bike to work she was hit-and-run by a car, dumb luck had it so that she was still conscious. Similarly I do sports like skateboarding, if by happenstance an accident happen and I'm knocked unconscious or otherwise unable to alert I can be found.