LiDAR and especially AR are both interesting features that (in the case of AR) have been touted for quite a while, but still don't seem to have any practical use for 99% of iPhone users. With all the research (and dollars) poured into them, I hope the payoff is big in the near future - but I don't see it.
I knew someone who made custom shoes. LIDAR would be perfect for in-home measurement. The downside is they need a super-expensive phone to do it, which they probably don't have.