A webbrowser is not something most people can or will switch out easily. Google could any day they want rewrite an API that brave depends on (like one used by adblockers) and it would instantly have caught lots of Barve users with a Bad Browser, many not knowing. Brave lives even more on the whim of Google than Mozilla does. It's like using Windows 10 with telemetry ripped out instead of switching to Linux. Good enough for some, not for all, bad to depend on in the long run for most.