Just be aware that you're placing a lot of trust in them.

It is adding a dependency on the Brave developers not to mess up and create security holes, in addition to whatever trust you place in the Chrome project itself. (A browser plugin requires somewhat less trust since it's sandboxed, but the permissions are still pretty scary.)

But I guess it's like buying an Android phone from anyone besides Google? Or installing packages from Debian and hoping they fix more security issues than they add, compared to the original developer. It's usually true, but not always.