In the Java/Groovy space, Jenkins and Gradle are the obvious ones.

I'm less familiar with the Lua world (not a gamedev), but this is an example of the kind of thing I'm imagining— a build system / task runner that's half lua and half C/C++: https://github.com/xmake-io

Having a modern on-prem replacement for Jenkins/Rundeck built in rust and exposing a roto interface rather than yaml definitions sounds like it would be great.

So, how is Rust better than these? What does it have that these lack?

Package management, expressiveness, community, open source code availability... a helpful compiler and goated type system.... overall sanity