Brave is known to take privacy (and security) more seriously than its contenders.
Nice, their marketing works. If you really cared about privacy you'd probably use something like Librewolf, which is not proprietary.
Excellent extensions like uBlock Origin heavily rely on Manifest v2 in order to do their bidding. Unfortunately, Chromium intends to stop supporting it.
It works without issues in Firefox and similar browsers like Librewolf.
Bleep bloop :'(