The question was closed and deleted by the post author, is thus generally not viewable, and thus scheduled to vanish. My feedback in comment reads (with disputed assertion bolded):
Sorry, but "How important is the DAG data structure to the future of our world, given that it seems to be central to technologies which are revolutionizing it?" is opinion-based, and only distantly related to cryptography. Mind you, a concept being used in cryptocurrencies does not make it related to cryptography; which is our only subject. Please make this a factual cryptographic question, or remove it. See this meta on cryptocurrency-related questions.
Argument towards the disputed assertion: the concept of currency is obviously used in and related to cryptocurrencies; yet it's far from as obviously related to cryptography, per Merriam-Webster definitions of cryptography and related.
Admittedly using mathematical terms out of their charted territory: "related to" is a symmetric but non-transitive relation.
My comment and assertion were intended to help improve the question. I later realized I once used DAGs in a cryptanalytic attack (that's far from typical), and IIRC then rescinded my first and perhaps hasty closing, thinking it was possible to improve the question.
A comment by another contributor justifies closing the question with: "because it is a general and non-specific question about an elementary data structure used in countless applications throughout computer science, not just cryptography".