Big things are not the same as small things, and should not be treated the same.
So I guess you're advocating that this dynamic equilibrium and "circle of life" is just panglossian optimal?
So far, I've noticed Brave Search only shows sidebar results for Stackoverflow and a few other popular forums that do not advertise on their pages directly, nothing else. So they're not really taking any revenue away. As for npmjs thing, I'm not sure if their revenue is hurt in any way because to view the package documentation you still need to open the link. Brave Search just provides you a copy command button extra for convenience.
As for discussions, they do not give full context so you always need to click the link so that's great for website owners as they get more exposure and traffic too.
At this point, Brave Search features are more on the UX side of things than anti-competitive so I personally will hold off the tinfoil hat for now.