probablyProbably many thmstheorems and applications of math that dontdon't explicitly refer to hypergraphs are actually related to them implicitly & could be recast in those terms. becauseBecause hypergraphs are equivalently just "sets of sets". inIn this way they're also often interchangeable with/analogous to a 2d boolean array in computer science (and how ubiquitous is that structure in both software and mathematics? inIn computer science it might be referred to as a "design pattern" or even just a simple "discrete structure").
hereHere is one key appearance/application of hypergraphs not mentioned so far. the erdos-radoThe Erdős–Rado sunflower lemmas[1], a key discovery of extremal graph/set theory, are about an intrinsic order or emergent "structure" to "random" hypergraphs if certain somewhat modest constraints are satisfied. this lemma showsThese lemmas show up in numerous important lower bounds proofs in monotone circuit theory in computer science, including new versions that strengthen or generalize the lemma.[2]
becauseBecause of their particular role in these "bottleneck"-type proofs itsit's not outlandish to conjecture that variations might be crucial in some future-established comp scicomputer science complexity class separations.
[1] erdos-radoErdős–Rado sunflowers survey/refs, TCS.se
[2] The Monotone Complexity of k$k$-Clique on Random Graphs by Rossman, containing new stronger lemmas on "quasi sunflowers"
[3] Razborov's method of approximations by WT Gowers