Rust is a continuous additional investment of time which will need to happen when writing the code, changing the code, doing the massive refactorings you mentio

Rust is a continuous additional investment of time which will need to happen when writing the code, changing the code, doing the massive refactorings you mention and last but not least when reading the code. There are benefits to that investment, but likely only in specific kinds of software (such as browsers, kernels, etc) which are relentlessly attacked and for specific kinds of programmers that like to specify things in much detail and don’t mind the associated costs. The friction comes from pushing Rust as a generic solution for most programmers. See the Rust in the backend efforts for the perfect example.