This is a bit like saying "writing your own embedded mini-language and interpreter is better since you can make it do arbitrary things".

The question is whether you want people on a large project spending time on custom tools? There's benefit in simplicity and standardization. Using Rust (to pick a nicer example than JavaScript) and the community's standard language tools does have its advantages.

I say this as someone who likes to work on language tools. It's fun, but I wouldn't call it productive, unless you work on tools with a large userbase.