The problem with brave is that it takes away creators freedom of choice when it comes to revenue for their content. It's nicely summed up in this article:
https://practicaltypography.com/the-cowardice-of-brave.html
TL;DR: Creators have to sign-up to brave's BAT system in order to get revenue for ads that Brave embeds on the creator's website. And even then there is a competition upon creators for users to spend money on them which is not correclating with the time users spend on creator's content.