Couple items:

- You don't need a cloud key, or any other hardware to use the Unifi APs. You can SSH in or configure with an app on your phone. But you miss out on a lot of the features that make this hardware desirable. I ran a Unifi system for a long time with no controller or cloud key at all.

- I've never needed an internet connection to set up a Unifi system, in fact I typically get the local network setup and working, and configure the WAN as a last step. This provides the convenience of being able to consistently hit the router to debug issues.

- I can see the frustration of not being able to migrate the configuration from cloud key to gateway, but a migration is different from a restore, which is what a back up is intended to provide. In practice, I'd always plan to reconfigure if I'm changing hardware or software in the stack.

Unifi is indeed very Apple like (founded by ex-apple engineer I believe?) in both good and bad ways. I think their goldilocks deployment is large home / small businesses that need remote administration.