Even Chromium started with WebKit which itself was a fork. This doesn't mean you shouldn't be interested in browser dev but you also don't have to do a totally clean sheet implementation.
This article appears to be entirely about an implementation from scratch.
It makes very clear that it is not about forking Chromium.
But even Google was smart enough not to start from scratch.
So again, I don't know who the intended audience for this article is. It's advice on something no sane person or organization would ever do.
I admire any team-of-one that takes on this endeavor and publishes their work.