Private LTE/5g is huge in the energy sector. You'll find it deployed for various IoT and end user devices at oil fields, offshore rigs, and even in parallel to the major carriers in large metro areas. The latter is fairly common with energy utility providers. One of the US's largest energy suppliers in the South operates what is probably the largest private LTE deployment in North America, using their own transmission towers to cover a majority of two states in the US Southeast. In addition to using this to support their own ops, they lease access out to other businesses.

It's also increasingly common to see private LTE/5g deployed to support municipal government operations.

One use-case is that LTE/5G are becoming increasingly attractive as a replacement for land-mobile radio. It used to be sort of common for major cities to have commercial MotoTRBO/OpenSky/iDEN networks for all kinds of business users that wanted LMR without having to pay to install their own equipment. Most of them died out due to stagnation of the technology and competition from cellular providers. There's a bit of excitement that that business sector could be coming back, as cellular equipment gets less expensive and increased data-centric usage has made quality of service on the mainstream cellular networks much more variable.

Almost all major cities operate a private LTE network for city agency use, for example. But for various reasons it's mostly been out of the reach of private ventures. This could be one piece of changing that (5G brings a number of the other pieces).

There's use cases further down the page. A fair amount of companies have existing applications that are on-prem and could be made to work with mobile devices this way without having to expose endpoints to the internet. Things like mobile barcode scanners, iot sensors, roving employees with tablets, etc.

Edit: Though there are other options: https://news.ycombinator.com/item?id=29395370

They outline a few cool business cases. I imagine it could be used by mining corps who are often in the middle of no-where. Set up your own cellular tower and give everyone Amazon branded sim cards and it will be a hell of a lot better than Wi-Fi in specific buildings and/or radio only communications.

They talk about it on their webpage, but I've heard this described as the ability to offer an SLA on a wireless network. This means that rather than using hard wired ethernet, company's can instead use a 5G network under their control and offer equivalent level of reliability.

I would imagine that Amazon is already using this service internally to support their Amazon.com marketplace effort. If I were to take a stab at Amazon's internal use case for a private 5g network, I would bet they are using it to manage the communications of the Amazon Logistics applications.

Amazon has come to not be held hostage and rely on outside companies for services all throughout their vertical including Fulfillment, Cloud Computing, and Logistics and Delivery. They have abstracted out their core operational dependencies into their own service offerings, so why not a private 5g network next?

If only the linked-to page had a section clearly headed "Use cases"

/s

anything big enough that connecting it using wifi might be challenging. E.g. Port, factories, airports, ...