In theory it would be nice to have one tool for all languages but I think it's never going to be practical because programming languages can be different in arbitrary ways. I can't imagine how the same tool could ever be ergonomic for managing projects written in C++, Scheme, Haskell and Bash for example. Mise (and other tools for managing development environments like Flox and asdf – I prefer Flox myself) only implement a subset of the features of languages specific tools like cargo/uv/rv. For example cargo can do all of this out of the box (and you can also extend it with more subcommands):

* manage dependencies

* format and lint code

* publish package on crates.io

* open the project documentation

* install binaries

* build/run the project

* run tests

* run benchmarks

Uv/rv don't (yet?) do all of that but they also manage Ruby/Python versions (which is done separately by rustup in Rust).