Luckily it isn't the only public DNS.

8.8.8.8, 9.9.9.9, and many others exist.

Here it's Cloudflare the CDN, sitting in front of Anna's Archive, that's doing the blocking. The DNS resolver used doesn't come into play.

(Case in point, I am using Google's DNS, yet still encounter the block when accessing from a Belgian IP.)

Touché!

We should stop using public DNS and start using our own DNS.