While hypothetically useful if it were Harvard bus lines, grandma and disabled people won't be able to understand this.
While it maybe efficient like Haskell or Nix, the popularity potential of it is impaired by being too abstract for enough people to reason about it easily.
I’m not sure this is a good comparison. Nix competes with a ton of other os, most of whom are established. If you had only nix, which most people agree is generally an excellent Unix distribution if a bit opaque, you would have an excellent Unix distribution that wouldn’t be opaque any more because everyone knows how to use it. The lack of choice in transit system labeling allows you to choose something that has a higher initial cognitive load but has a lower amortized load and/or provides superior information etc simply because people have no choice but climb the learning curve. And once it’s become part of a regional culture it ceases to have a learning curve at all and is simply superior to the alternatives (like nix)
While it maybe efficient like Haskell or Nix, the popularity potential of it is impaired by being too abstract for enough people to reason about it easily.
https://en.wikipedia.org/wiki/Worse_is_better