Please define "best"? Certainly, it's not the power efficiency. Not memory efficiency either. Performance maybe? But then it's very different from test to test. So, what makes Chromium the best?
I can't speak for the parent, but when most people say this they mean "least likely to break my websites", completely ignoring that this is a symptom, not a cause, of Chrome's dominance. Even my health insurance website breaks in Firefox, and their error message suggests that everyone should just use Chrome. We'll end up back in the early 2000s Internet Explorer situation eventually before the pendulum swings around again.
Best would be the one that users choose to use, when they are given the option and full power to do so.
Geeks like us know that iOS Chrome is using WebKit to render instead of Blink. But that is not relevant to most users.
They cannot choose the actual chrome that would be in iOS if it was allowed.
Microsoft, just like Apple, engaged in anti-competitive practices that prevented user choice.
The solution to both of these situations, is either the courts force apple to allow user choice, just like it forced Microsoft, or for new laws to be created to do something similar.
Microsoft was literally brought to court, and a judge said that their practices were anti competitive.
So yes, the legal system said that Microsoft was anti-competitive.
You should go read up on the court case, because it is an absolutely true fact that a judge ruled that Microsoft engaged in anti-competitive practices.
And now there are new laws, in the EU, that will prevent Apple from engaging in anti-competitive practices as well.