This series on profiling various bits of the JS ecosystem is so interesting.

https://marvinh.dev/blog/speeding-up-javascript-ecosystem-part-3/

So many libraries in our ecosystem suffer from this issue. I really wish there was a way to update them all with one click. Maybe we need a reverse transpiler which detects down transpilation patterns and converts it back to modern code again.

The post goes deeper into this further on, but it’s amazing how much is lost in translating between layers, and makes one think about how much perf is gained simply from discarding out-of-date assumptions in rewrites rather than other improvements that are more technical in nature.