We had many languages that are faster that are not c/c++.

Compare Go (esbuild) to webpack (JS), its over 100x faster easily.

For a dev time matters, but is relative, waiting 50sec for a webpack build compared to 50ms with a Go toolchain is life changing.

But for a dev waiting 50ms or 20ms does not matter. At all.

So the conclusion is javascript devs like hype, and flooded Rust and built tooling for JS in Rust. They could have used any other compiled languge and get near the same peformance computer-time-wise, or the exact same time human-timewise.