I'd say that IAM is a too low-level interface (or language). It makes it hard for engineers to think at the convenient enough level of abstraction correctly. (Imagine writing e.g. a C++ compiler in 6502 assembly.)
An obvious solution would be to introduce a tool / language which allows to operate at the level engineers are used to think at, validate the structure, and analyze the potential breach impact for every resulting piece. (Sort of like, again, a compiler. Or at least something like Terraform as a first step.)
A few steps in that direction are already done with the tools mentioned in the original thread. But I suspect that a lot can still be done in this area, bringing fame and potentially money to those who would come up with a tool which becomes widespread. (I mean, it could be a wide project / startup idea for those who understand both IAM and formal methods well.)