I view Brave as very healthy competition to Chrome and Edge. Yes, it's based on Chromium. But it disables the many egregious privacy violations, as well as other bad things.
And whatever Google decides they want to implement or support in Chromium will be the web default, even just how they interpret ambiguities or undefined behaviours - standards be damned. We have tried this before and it was not pretty.
That is why we need competing browser implementations.
I'd argue for the opposite - we need strong standards and some methods to strictly enforce them. Governments could do that but the level of incompetency and politics are huge roadblocks
We have strong standards - but if there is only one implementation, that quickly becomes the standard no matter the text in the actual formalised standard.
Chrome does its own stuff. Lately, they added a tracking different from cookies, something that Brave has said they won't be adding. I want the market to segregate at every level.
Brave and a few other derivatives will block these high profile features. But they don't have the resources to maintain many of these exceptions. For example look at Brave's response to manifest v2. They say that they will try to support it for longer but they are careful to promise little. Because they know they don't have the resources to maintain all of the underlying APIs and their own extension store.
Plus this helps entrench Chromium as the only browser engine. Because even the addition of many non-harmful features that other engines don't implement create compatibility issues that results in developers using these new features so sites break. Firefox gets unsupported so people have to switch to Chrome or a derivative.
So yes, a derivative is better than using Google Chrome. But it is a small improvement compared to switching to a different browser engine.