As far as web ads go, a lot of people's objection to them is not seeing ads (though the ads themselves can obviously be very invasive and bothersome), but to things like tracking and fingerprinting, which the company is adamantly against. The attempt is to have ads, but also have privacy, which IMO is the correct move. It's not like we can run everything on subscriptions.
> Brave replaces the ads from the website with its own ads.
This is not exactly true. They have separate functions for an adblocker, an ad delivery system that's entirely separate from the websites you visit, and a tipping system for sending BAT to creators.
I'm not terribly fond of crypto, so I use Brave as essentially a degoogled Chromium with a built-in adblocker that won't get fucked over by Manifest v3 (since it's not an extension) and is available on mobile, and who run an independent end to end encrypted sync service. It's pretty nice.
I don't totally understand how people think Brave is against ad-tech, when it is very much an ad-tech company making money primarily from ads, and secondly from its crypto ownership in BAT.
Brave does a lot of user tracking, but it says it anonymizes it, which hopefully it does, but it still tracks all your behavior.
It is still a cool model, but very much ad-tech and ad-based.