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.
More on topic, they still use Bing's near-useless image search, so even if it's getting worse Google Images is seemingly the only decent option in that category.
The results quality has gone down and it's noticeable only after you switch to another independent search engine, like Brave Search.
For example, search for the term: "javascript undefined vs null" on Google and Brave Search. Brave Search gives way more information in the sidebar and Google doesn't at all.
The discussions feature on Brave Search is great, you don't even need to append queries like 'stackoverflow' or 'reddit' for searching discussions.
On top of that, let's say you're trying to search for an npm library like 'react-select', if you search that term on Brave Search, it gives you a button to copy `npm install react-select` right below the npmjs.com link.
It's crazy how good Brave Search is compared to Google sometimes, haven't used Google Search in a long time because of it.