Oh there is definitely a need for invalidation sometimes, but the system doesn't support it, due to its openness: authoritative servers don't track their consum

Oh there is definitely a need for invalidation sometimes, but the system doesn't support it, due to its openness: authoritative servers don't track their consumers. But the protocol does support it. So, if you really need invalidation, go talk to the world's resolvers and ask them to process dns NOTIFYs from your authoritative DNS servers.