I use an EdgeRouterX. It is also made by Ubiquiti but the Edge series is quite different from Unifi, seems more to be targeted at maybe ISPs, it has a built-in management UI and does not require (or work with) a Unifi controller. I also use a Zyxel switch with PoE to power the U6 Lite.

I think the main point is that it should not and does not matter what you use. You can mix and match anything you want if those devices work on their own and do not require any central management.

I do not need or want some Unifi controller and being able to look at data about my devices and being locked into their products, I just want devices that want that I configure once and forget about them.