Correct me if I’m wrong but, I think Brave Ads are opt-in. I have brave installed (although I use Librewolf as my main browser) and I’ve never seen an ad, you just need to disable them from the settings. Ads are just for those who want to earn BAT (the weird crypto token) by seeing ads.
https://en.wikipedia.org/wiki/Betteridge’s_law_of_headlines#Studies