Default settings use remote, shared DNS caches run by an advertising company.
Regardless, this is a step in the right direction. DNS is highly effective for this filtering out advertising.
Personally I just run my own authoritative nameserver(s) with all the IP addresses I need. No recursive cache.
When I browse to websites where I have never been and may not return, I am never using graphical browser that loads "resources" automatically from any random domain.
I am using a browser I compiled myself. I am only reading text.
Binary resources, e.g., video, can be downloaded non-interactively with an ftp/http client.
If it is an important website that I use repeatedly, then I have all the IP addresses for the resources the website's pages will need stored in a zone files. Then it is "safe" to use a browser written by an organization company that makes money from ads. All DNS requests are answered by my server(s).
I can retrieve (refresh) the IP addresses for my zone files very quickly with custom software I wrote to do this. My lookups are faster than a cold recursive cache and send out fewer requests.
IMO, the way to think about "ad-blocking" is not to try to imagine how to block every possible ad server. Instead, just focus on what web content you want and figure out what addresses you need to get it.
At one point a certain browser written by an advertising company had its own DNS resolver. Imagine your /etc/resolv.conf being completely ignored. Food for thought.