I agree with you on the amount of technical knowledge that's needed. I guess routers/home internet security might be ready for some shakeup if someone comes up with a layman-ready interface while being secure.

But, the point of having a firewall is that you can find tune the outgoing IP addresses. Sure, it'll take some time to initially allow all IP addresses for a specific devices, but it shouldn't be undoable. There are lists out there which specify which service owns which IP.

The sole point of a good firewall _is_ that it can only access Netflix and not any unwanted servers.