If you are wondering why not Rust instead of Go, they outline why Rust was not chosen. This is a port not a reimplementation. Many of the data structures can not easily be ported to Rust, such as Nodes with cyclic dependencies. Check the longer interview here: https://www.youtube.com/watch?v=10qowKUW82U&ab_channel=Michi...
Also, I think the discussion on esbuild's choice of language applies here as well as it has a large similarity. You can find it here on hn