I don't agree with the problem they aim to solve with those goals.

But today it takes several years of mastering tools and frameworks to get to that stage. HTML First principles should allow people to unlock that feeling, and level of mastery, much earlier on in their coding journey.

The onboarding process can be made easier for devs new to the project (junior or senior) with decent documentation. Just enough install/build the project in their local machine and understand the gist of the technologies.