Bured lede: i7 CPUs for border patrol.. why?

For the same reasons fortune 500s will spec the same for their office workers. Labor is expensive compared to hardware. It is often cheaper to spend a little bit more on hardware to avoid supporting multiple configuration, exceptions, more frequent updates, support tickets from power users, etc

If you pinch pennies buying a spec that exactly meets today’s needs, and next year MS Teams releases a new update that requires more resources, you don’t want to buy a whole building full of new computers.

i7 CPUs have been used for all sorts of PC configurations. Your standard library at a university or college, the office worker desktop who does nothing but use web based applications for their job, and so on.

The pricing difference between an i5 and an i7 aren't really that big when you go to Dell and tell them I need 4,000 desktops. DHS isn't paying the same pricing difference as we would be when purchasing a boxed CPU.

At a certain scale, the relative complexity (both in terms of inventory management and dealing with upgrade requests / approvals / etc) tends itself towards picking a baseline spec that can work for the overwhelming majority of your fleet.

It's just a typical enterprise PC configuration. Probably because nobody writes efficient software these days.