One slightly annoying thing about esbuild/swc is that they're faster by literally not being equivalent to Babel. esbuild intentionally does not emit ASTs, and S

One slightly annoying thing about esbuild/swc is that they're faster by literally not being equivalent to Babel. esbuild intentionally does not emit ASTs, and SWC has their own flavor that is not compatible with Babel. Furthermore, both are written in non-JS languages, meaning any sort of plugin system either has to be written in Go/Rust respectively, or suffer massive performance hits from crossing the JS runtime boundary. SWC abandoned plugins in JS for this reason. The dirty secret is, as Sucrase (https://github.com/alangpierce/sucrase https://github.com/alangpierce/sucrase) reveals, just that Babel is slow and the codebase really pays homage to the project name. Simply computing the config for transforms takes dozens of milliseconds on my machine as it does a bunch of filesystem reads. So esbuild/swc etc. aren't gaining some magical compiled language speedup, they're just... not doing the dumb things that Babel is. Not ragging on Babel here, it's a 7 year old project originally written by a guy fresh out of high school. I bet a ground up rewrite of Babel could accomplish the same.