No, Rust is not at the paretto frontier for your mentioned 1, 2, 3 and also 4 compilation speed. It could have all of those things and also just have faster compilation. Rust devs have talked about how they have some regrets about not optimizing more for compilation, but instead another attribute got optimized in terms of paretto efficiency - the language's development time. Arguably I think that is the single worst trait you can optimize for in language development, because by saving a little time developing the language you cost humanity, let's say hundreds of millions of hours of development time downstream from you, with millions of users being less productive.