Isn't Brave Ads opt-in? You can still use Brave as you have been.
But the whole reason “pay for ad-free experience” model isn't dominant is that advertisers, in fact, are willing to pay more for exactly the people that would pay the most to opt out of ads (because those are the people with the most money), not pay more for the people who would opt in to ads. So the premise is known to be the opposite of the truth.