yep, the point though is that having a build step during dev adds some overhead (which can easily go into the several seconds range in my experience) into the type-save-reload cycle, which is exacerbated by hit-reload-before-build-finished-so-need-to-reload-again pattern.
My understanding is that this tool removes that entire class of annoyances, and gives a no-hassle live-reload ES6-enabled environment on top.
The build step is mitigated by incremental reloading, and the incremental reloading can be tied to a live-reload event.
So you end up with the same workflow as shown in this video; but most likely faster for many modules (browser requests 1 JS file rather than potentially hundreds) and also more realistic for production (aside from minification, the dev environment is the exact same as the production environment).
My understanding is that this tool removes that entire class of annoyances, and gives a no-hassle live-reload ES6-enabled environment on top.