"Language X is slow and we could save Y switching to Z" is always a false promise. The thing that keeps software interesting for me is that there are almost no

"Language X is slow and we could save Y switching to Z" is always a false promise. The thing that keeps software interesting for me is that there are almost no absolute rules. So I'll agree that complete rewrites are usually a mistake and performance problems are often not in the language. But I can't agree that rewrites are always a mistake. esbuild is a recent good example of how much difference switching to a faster language can make.