It's enlightening when you see all the crap that all the devices on your network are doing. You can take things a step further and isolate IOT devices on isolated subnets, with additional firewall/security rules to create a choke point for all traffic.
Only a matter of time before applications begin to roll their own encrypted forms of DNS in order to circumvent ad blockers.
That's when the apps start embedding(pinning) certificates and completely ignoring any additional root certs you might want them to accept from the OS.
That's when you start injecting your own certificate into the certificate verification APIs... one of the amazing powers you get when you're root and actually have full control of your device, no wonder it scares big (ad)tech for users to have that power.
I think this is the biggest piece that gets overlooked by many. I still remember the first time I ran pihole and saw all the stuff attempted and blocked. It is one thing to know all those connections are made in theory. It is so radicalizing to see it first hand on your home network.
My xbox turns itself on all the time entirely randomly. Most mornings its already turned on. I will be in the next room and hear the startup beep go off. I don't know if its a faulty switch or maybe I should put on a tinfoil hat.