i agree w/ the the complexity analysis point, but that theoretical understanding actually translates to real world deployment decisions in both subfields. knowing an algorithm is O() tells you surprisingly little about whether itll actually outperform alternatives on real hardware with real cache hierarchies, branch predictors, and memory access patterns. same thing with ML (just with the very different nature of GPU hw), both subfields hve massive graveyards of "improvements" that looked great on paper (or in controlled environments) but never made it into production systems. arxiv is full of architecture tweaks showing SOTA on some benchmark and the same w/ novels data structures/algorithms that nobody ever uses at scale.
I think you missed the point. Proving something is optimal, is a much higher bar than just knowing how the hell the algorithm gets from inputs to outputs in a reasonable way. Even concurrent systems and algorithm bounds under input distributions have well established ways to evaluate them. There is literally no theoretical framework for how a neural network churns out answers from inputs, other than the most fundamental "matrix algebra". Big O, Theta, Omega, and asymptotic performance are all sound theoretical methods to evaluate algorithms. We don't have anything even that good for neural networks.
