It’s worth noting that wireless transfer does not mean “cloud storage”. It can, and often does, but it is also easy to wirelessly back up things like photos entirely locally. With most prebuilt NAS units, all you have to do is buy something like a synology, some of them even come prefilled with hard drives, and go through the wizard in the app. That’s it, and the app will wirelessly, automatically back up things like pictures to your own locally controlled storage. I’m pretty sure you can do it natively with Time Machine too if you really wanted.