Obviously, it's great that we get tools that provides such improvements, but somehow I feel that JS should not be that slow. I expect it to be about 3 to 5 times slower than lower-level languages, but when the difference exceeds 10 times, it means that the Babel's code is not written very efficiently. Another thing, is that usually you only need to optimize a few critical places, and that will give the biggest improvement. So I wonder if it is possible to optimize or rewrite some parts of Babel into a faster language, but keep all of its extensibility and ecosystem. Maybe projects like esbuild or swc will provide insights for Babels' team.