Created by: Timer
After the cache is warm, it is possible for thread-loader to hurt speed. thread-loader also has leaky interaction with its workers, giving us some junk output here and there.
This will hurt cold boots/builds the most, but with our cache rules it should be very seldom someone needs to clear their cache (if ever).
Per https://github.com/facebook/create-react-app/issues/5138#issuecomment-425631999, future work is to write our own worker that handles caching and parallelization.
Fixes #5138 (closed)