[kibwen]

It would only be a difficulty for intercepting devices like PiHoles (and I don't think it's an insurmountable difficulty either, if you control both the Pi and the computer). It wouldn't affect browser-based adblockers, which is how the majority of adblocking is already done, because browsers already have access to the unencrypted request.

[15characterslon]

That would be my point too. DNS-based content blocking is very ineffective and can be outsmarted very easily.

DNS filters might be very easy to set up but if they become more major they can be outsmarted very easily - what if Google starts serving ads from www.google.com, would you block that domain name too? Browser extensions can block content far more precisely.

And smart TVs and such stuff could easily switch resolvers and just not use your Pihole's DNS resolver - that would work even without DoH as long as you don't intercept traffic on your router. E.g. Fire TV already adds Google DNS as an additional DNS server (you can't change that). Chromecast only uses Google DNS (AFAIK you can't change that either). I guess the only viable option here is just not to buy those products.

[tty2300]

Or just intercept and redirect requests to googles DNS.