While I let my smart TV connect to the internet for firmware update reasons (bug fixes), I’m running my entire home network through NextDNS, and before that a PiHole. Not seeing any ads in the UI, and I note some attempted logging traffic is blocked. Before I upgraded to LG last year I had a Samsung and it was trying to ping home constantly. It constituted 80% of outbound requests denied by the PiHole
Out of interest - Why do you use both a PiHole and NextDNS? I removed my PiHole once I got NextDNS as it just seemed redundant.
I can't install NextDNS client on a lot of devices like a robot vacuum. Sure you can configure NextDNS to be the resolver on the gateway, but then the gateway becomes the only client in your NextDNS logs and you can't figure out which device is downloading Google ads, which makes the log useless. It is also easier to temporarily disable filters -- changing DNS on some routers may need a rebooting, which causes downtime on the whole home network.
The only thing you can do with NextDNS logs is looking at them on NextDNS web UI. I had a lot of fun messing with my local AdGuardHome logs with visualizations, analysis, and alerting.