I have a 55" commercial LG "Wallpaper" OLED and it is "dumb" and gorgeous – and mounts flat to the wall at only 4mm thick! No 4K, no HDR, don't miss them a bit. No apps, no ads, no features at all really; one HDMI in, which I have connected to an Apple TV via a Denon HEOS AVR.
Yea. I picked up a CX, and holy moly, I’d miss 4K, HDR, VRR, and the response time.
These commercial units are great; but you aren’t just losing the dumb apps and potential spying/metrics/whatever. You always miss out on real features too.
I paid $1800 for a 65CX and immediately black holed its MAC address at the router. I love it.
A pi-hole operates (usually) by intercepting DNS requests and returning bogus results if the request is for a known ad host. That's an application layer activity; other requests for non-ad (or unknown ad) hosts would succeed. So a pi-hole blocks some application layer activity but not all.
MAC addresses are a link layer concept, and a router is a network layer device. Having a MAC address blocked at a router would prevent that MAC address from using the router's function, which in this context means that the device holding that MAC address (the tv) would be unable to send and receive data through the router at all; the TV would be unable to access any site on the internet, ad-related or not.
Depending on what other devices you have on your local network which you might want to use with your TV, it might be easier to just not plug the TV into the network at all.
If I'm not misunderstanding things, a PiHole only "works" if the device actually use it for DNS. If the device uses hardcoded (or whatever) DNS-servers the lookups will bypass your PiHole.