It’s location accuracy improvements in urban and indoor areas, which is notoriously poor.

UWB is supposed to let you know how far away other devices are, and in what direction. This will let you e.g. find your device if you left it somewhere in your house, or give you an UI to Airdrop to someone next to you (rather than just showing everyone in range), etc. Other location services are supposed to let you navigate indoors.

I don’t think there’s really “the next play” as much as there’s a bunch of marginal improvements, and a bunch of people who hope that there will be some killer app for location services that they can dominate.

I can see a lot of value for big brands / retail, where location tracking via bluetooth etc already exists. Same with FB offline conversion tracking, walk into store after seeing an ad analytics etc.

And I think Apple envisions value when combined with AR

I assume it's being able to track an object, with extremely high precision, anywhere in the world (that's populated) without relying on a data or GPS network. That seems huge to me.

What is the problem with using GPS?

GPS works poorly in urban areas (newer chipsets are better at this, but it’s still rough) and doesn’t really work indoors at all. GPS will tell you that your phone is at home, UWB will tell you that it’s on the dresser in the bedroom.

GPS will tell a device where itself is. The device still needs to go online to tell anyone else where it is.

This, IIUC, will tell you where a thing is without it being online.

Being able to track the location of objects (or other people) through walls, for displaying in AR glasses. That's my guess.

You can't turn off Apple's version of this already.