I agree with the post, but it should be noted that there's a big difference between Chromium -- an open source project -- and IE 6 being the de-facto browser engine on the web.
I think the difference is mostly theoretical. Consider the proposed extension changes: no one seems to like them, but Google will be able to push them through anyways. Maintaining a Chromium fork is a huge undertaking that only a few companies would be willing to invest in.
Maintaining a fork is much less of an undertaking, than reimplementing all Chromium quirks. Hence plenty of Chromium forks exist, but only one last barely competing browser.
No nontrivial Chromium forks exist, to my knowledge. Do you know of any?
I don't think Opera, Vivaldi, Brave, Yandex browser are trivial by any measure. Heck, even something small and independent, like ungoogled-chromium, is in no way trivial.
I haven't checked, but it was my understanding that – outside of the UX – these are all very shallow forks.
Does anyone know more about this?
Yes, these are all very shallow forks that mostly “just” change UI. That guy doesn’t understand what nontrivial means.