I'd argue its far more trustworthy than modern day Firefox/Mozilla, they're not exactly the second coming these days.
What makes Firefox more trustworthy?
Yeah it's true that Mozilla's mostly financed from Google's anti-antitrust payments, but at least they actually made something of their own and have a trustworthy track record three decades long as a non-profit and Netscape before that.
Tell me I can turn off the evil intent, and not just one of its manifestations, and we're in business. But you can't tell me that.
Once you've done that you're back to the same old question - why is <other browser> any better/safe/trustworth than Brave, which is arguably the only one that's gone out of their way to make sure its sustainable and not reliant on farming user data to the highest broker.
That right there sours your whole argument. Your entire reasoning here is based on "they're probably doing something dodgy", ignoring the bit about it being opensource, or that Firefox and Chrome are at the very minimum on equal terms of "dodgyness", as you'll no doubt already know.