Brave is known to take privacy (and security) more seriously than its contenders. It’s therefore unsurprising to find it recommended by Privacy Guides.
At least in the privacy community, Brave isn’t super popular. It feels more geared towards the “hyped crypto early adopters”. Brave inclusion in privacy guides has always been controversial.
Brave is ultimately an advertising company, they base their business model in ads. And everyone knows how bad that can turn.
Ungoogled Chromium on the other hand takes patches from brave and other Chromium based browsers, removing every bit of telemetry and giving you the cleanest experience you can get on Chromium, without relying on a shady company.