Interesting layer of security and method to reduce threats, ads and bandwidth usage.
I have posted about Open / Public DNS and Secure or Private DNS and related but those didn’t reduce ads and bandwidth usage.
Some things may need to be added to white list to allow some streaming services that require ads to work like Netflix, Amazon Video and likely others if you use any of these.
https://blog.apt-secure.ca/2020/09/an-introduction-dns-sinkholes-pi-hole.html