There is a lot of work to be done still. I don't think we are anywhere close yet, especially cause I still need to understand how it works fully.
I'm a firm believer in a single compilation "unit", vs a task runner with excplicitly declared dependencies, that have to be "by hand" linked together. You gain a lot of overhead this way.
My thoughts are, what if you could compose, multiple webpack compilations, so you could have "separate" runnable build envs, but when deploying, can be one compilation for maximum performance.