“Just” fork it. Right.

It’s a massive undertaking to maintain a fork of something that large and continue pulling in patches of later developments.

Not to say that Brave doesn’t have the resources to do so - I really don’t know their scale - but this notion of “just fork” gets thrown around a lot with these kinds of scenarios. It’s an idealistic view and the noble goal of open source software, but in practical and pragmatic terms it doesn’t always win, because it takes time and effort and resources that may not just be available.