The closer the transpiled language to JS the lower the impedance mismatch. Whatever language I write in, I may need to dive into debugging it as JS. Whatever language I write in, I likely have to use/adapt JS code samples from libraries and dependencies written in JS. More often than not that's a paper-cut; Haskell often has a huge impedance mismatch from x86 assembly but you can still debug it pretty well and FFI into assembly libraries with varying levels of ease based on library documentation.

But especially when you are working with other developers and a mixture of skill levels, impedance mismatches are useful paper-cuts to try to minimize.