You're not paying attention

Apple NAS: https://www.walmart.com/ip/Apple-AirPort-Time-Capsule-2TB-St...

Apple 802.11ac wireless AP: https://www.priceblaze.com/me918ll-a-Apple-Network-Routers?r...

Apple TV: https://www.apple.com/apple-tv-4k/

I was wrong about printers though. They just have their own proprietary printer protocol in air print

And how do you know those biometrics stay on device? How do you know they will continue to stay on the device? It's not your kernel. It's THEIR kernel. They can do whatever they want.