HTTP2 improves on that bottleneck but not as much as expected. I'm struggling to find relevant benchmarks now, but anecdotally even on localhost when using a dev pipeline without a bundler (such as Vite), any reasonably complex application takes many seconds to fetch thousands of small JS files.

This is something I’m facing now. Even hundreds of files slow things down. Code splitting is the answer, but that adds some other complexity that we may not want.