story
Rust requires designing the memory management (ownership/lifetimes) of a program, which Golang doesn't, so even if/when the cognitive load is (hypothetically) equal, there's an additional, non-trivial demand. This is not something that everybody wants in a project (the given tradeoff may not be worth); for sure, if I had to introduce a language in my team only for tooling purposes (ie. small programs), Rust would not be the most productive choice IMO.