What’s not private about the ads. Brave uses a pretty ingenious way of serving targeted ads.

All the tracking is local on the device. The browser is sent an ad bundle. The browser chooses what ads to display, locally.

Also viewing ads to support the product is opt in, not opt out.

Is there some ethical gray area around an ad blocker funding itself by displaying different ads. Sure. Is it automatically anti-privacy to serve ads? I’m not so sure it is.