Ubiquiti has had outages in the past that meant you couldn't manage the equipment right in front of you.
Even discounting the potential security implications of that kind of management, the rage I would feel in that situation is enough that I while my AP is nice, works great, I will never use any of their gateways.
I'm using a 2.5g protectli with OPNSense now, and it's easy to manage, and all local.
You can manage them as long as you have access to your controller. If you’re using the controller hosted in their cloud, then you’re beholden to their outages. Some gateways cannot use your own controller, so be mindful when selecting your gears.
I got a UDM SE. The controller runs on the device itself and can be used locally, without a Internet connection or Ubiquity account (i've only ever set up a local admin account on the controller).
It works great for me. UDM + 4 switches and 2 AP. All unify, I like the interface. But I'm also only doing basic stuff.
I've had a pfsense based setup in the past and liked it. Now that I got 10gb ftth, the UDM SE ticked all the boxes and I went with a full unify setup with the switch to 10gbit. Happy with it so far.