Some time ago, RFC 6106 was created, which states how a router tells the clients about the DNS server to be used. It is a new standard, it has to be implemented, which needs time etc.
I'm courious about the need for it: wouldn't have it been better to define a "globally valid" anycast address for DNS? Queries would be sent to this address and would be promoted along the default route until there is a host which claims to be responsible for it.
In an enterprise network, that would be a central DNS server (or even more, on really big companies); in a SOHO network, it would either be the router or the DNS server of the ISP, in a root server hosting data center, it would be the DNS of the hoster, etc.
What do I see wrong here? Do I have a wrong view of the anycast concept?