Isn't this an admission the internet is not safe by default, and you need specialized knowledge and hardware to make the Internet safe(r)? Xfinity/Comcast hardware (cable and WiFi integrated) works with the Pi-hole how? I can't change the DNS addresses on Xfinity hardware. Ok so I have to buy my own router, in which case Xfinity blames all problems on running by own hardware. Another ISP with which I'm familiar, when…
Once the pihole has been setup and has an IP it becomes a DNS server, you just then tell your end devices to use the piholes ip address as the dns server.
DNS requests either go where you want (static IP addressing) or where to the xfinity/Comcast (DHCP addressing).
And no, the internet is not safe by default, by neither is the real world.