Learning when to invest in type constraints and when not to is an important lesson. It’s not unique to rust, though it might express a little differently. I’ve dealt with excessively typed c++ and excessively abstracted and typed Java and they have the same class of refactoring problems. I’ve also dealt with plenty of undertyped and under documented go, where there are specific values all over the place which turn into runtime footguns - and these can be truly dire to refactor as well, you get an earlier sense of progress but you ship bugs to users most of the time. There’s no magic answer to this set of trade offs. Rust gives you tools to mostly pick your place, on this specific axis it provides an unusually broad choice.