I mean, you don't. You have to trust the maintainers of the software you use, to a certain degree, or spend a majority of your time auditing the software you use.
That being said, Brave is pretty upfront about the security of their software. They've paid $25k in bug/security bounties so far and their browser is open source. So if an update turns evil, it stands to reason that someone is going to notice.
That being said, Brave is pretty upfront about the security of their software. They've paid $25k in bug/security bounties so far and their browser is open source. So if an update turns evil, it stands to reason that someone is going to notice.