What about a face is it that needs range information - the "R" in "lidaR"? Do people carry around models of someone else's face
Yes that is exactly how Face ID works, a 3D model of the face scanned with "infrared dots" - not exactly LIDAR, but similar.
However just as important is a big use of the rear LIDAR on phones - range finding for the camera! And 3D modeling a face in particular is precise focus on eyes, really useful in portrait mode.
There is also some use of 3D scanning of objects but I would say that's far less used than the range finding aspect (and the fact it does store a depth map with photos that can be used to apply artificially selective focus).
Tell me, which model of phone do you have which uses LIDAR?
From the link you provided:
The feature was later included in the iPhone 12 Pro lineup and subsequent Pro models.
So all those since I've had several since the 12 (always Pro or Pro Max models).
blinding them seems to fall outside the range of allowable behaviours.
In theory if you laid under a car just after it had driven the heat could kill you. Yet cars still exist.
There are all kinds of things that are allowed because the dangerous conditions are rare. Being close enough to LIDAR to get blinded would be one of them, it does seem pretty obvious to me as you say that if it could blind random passers-by on the street it would get banned... my original post is more worded about the rare case, that you get really close to the LIDAR unit to look at scratches in the cover or whatever, then is it a danger? It still seems like it might be but probably mostly not. I would personally try to be sure it was powered down before I got too close.