edit: from here https://news.ycombinator.com/item?id=19828702 I gather that this indeed harms CDNs outside the ones that Cloudflare has a business relationship with.
> EDNS IP subsets can be used to better geolocate responses for services that use DNS-based load balancing. However, 1.1.1.1 is delivered across Cloudflare’s entire network that today spans 180 cities. We publish the geolocation information of the IPs that we query from. That allows any network with less density than we have to properly return DNS-targeted results. For a relatively small operator like archive.is, there would be no loss in geo load balancing fidelity relying on the location of the Cloudflare PoP in lieu of EDNS IP subnets.
> We are working with the small number of networks with a higher network/ISP density than Cloudflare (e.g., Netflix, Facebook, Google/YouTube) to come up with an EDNS IP Subnet alternative that gets them the information they need for geolocation targeting without risking user privacy and security. Those conversations have been productive and are ongoing. If archive.is has suggestions along these lines, we’d be happy to consider them.
There's nothing incorrect about what Cloudflare is doing, EDNS does not require ECS data to be included in requests, but for whatever reason the maintainer of Archive.is decided to block 1.1.1.1 over it.