It has an alternate low-power mode that only provides a few basic functions (presumably phone, text, maybe a basic web browser?). When running in "regular" Android mode it won't reach those numbers (although I believe it still claims to do better than most phones in that mode).
It only needs to be able to make/receive calls to be called a phone, right? Why would it be more expensive?
You can get a Garmin inReach emergency "phone" that gives calls + text over satellite and has a 25 day battery life.
I mean, a classic old Nokia easily ticks all those boxes, what's fishy about it?