No? They sell ad space, people buy ad space. Brave shows you ads, gets paid and keeps a cut from that payment, they give their users a cut from that payment. Brave has a tipping service which lets users tip sites they like. End result is advertisers can advertise, and people making content get some of the ad money, the setup's just built to not track people.

They're very straightforwardly ad salesmen like every other browser out there, they've just tried to build an ad ecosystem that doesn't track users.

And Firefox's business model is based on Ads - both models are just as scummy as each other.