I'd love some kind of meta-language that is easy to read and
write, easy to maintain - but fast. C, C++, Rust etc... are
not that easy to read, write and maintain.
Being maintainable comes down to code quality, comments, and documentation. These are thing that I really want to emphasize for this project but for now I'm just one guy and it's very early days so I have to focus developing core kernel components first.
Id argue that python, elixir, ruby and all manner of languages are easy to understand and maintain. I dont' have to think about memory management or buffer overuns. its much easier to avoid race conditions since I'm not stressing about low level details.
by that same definition, rust is pretty easy to maintain. I won't say its easy to write though.