I would say the reason the perf costs feel bad there is that the abstraction was unsuccessful. Throughtput isn't all that big a deal for a parser at all if you only need to parse the parts of the code that have actually changed
And anyway, these new tools tend to have a "perf cliff" where you get all the speed of the new tool as long as you stay away from the JS integration API sued to support the "long tail" of uses cases. Once you fall off the cliff though, you're back to the old slow-JS cost regime...
I don't have them at hand right now but there are various detailed write-ups from the maintainers of Vite, oxc, and more, that are addressing this specific argument to point out that indeed the JavaScript runtime was a hard limitation on the throughput they could achieve, making Rust a necessity to improve build speeds.
Why are we still treating batch processing as the controlling paradigm for tools that work on code. If we fully embraced incremental recomputation and shifted the focus to how to avoid re-doing the same work over and over, batch processing speed would become largely irrelevant as a metric
In want the JS toolchain to stay written in JS but I want to unify the design and architecture of all those tools you mentioned so that they can all use a common syntax tree format and so can share data, e.g. between the linter and the formatter or the bundler and the type checker.