I think this is spot on. The tooling is there for C++, but human mistakes are much more prevalent, and the discipline to apply the tooling is not a given.
There should be an industry push for certified Rust tooling, it would save the aerospace and auto industry billions. Or you could use the unsexy but also very good ADA 2012, which is already certified.
iirc, SPARK has proof capabilities that outstrip the memory-safety guarantees of Rust. basically design by contract, where you can check loop invariants and statically verify complex preconditions and postconditions.
I suppose the workflow would be to flesh out and check the abstract design in something like Coq or (maybe) TLAPS, generate a refinement into the SPARK code contracts, then implement the functions. Since the toolchains are verified there shouldn't be much surface area for bugs left.
There should be an industry push for certified Rust tooling, it would save the aerospace and auto industry billions. Or you could use the unsexy but also very good ADA 2012, which is already certified.