That's not a reasonable person. That's an ignorant conspiracy theorist whose reality is grounded in delusion because right now advertisers take what they want and what they can get and the average user is depending on the browser to pay whack-a-mole with the invasive privacy tech they build and it's not sustainable.
I'm afraid actually you are the ignorant corporate worshipper, whose reality is grounded in delusion, because ad tech companies will not ever stop using their already researched tracking and targeting techniques. For one, they have spent a lot of money on that research, the results are earning them a lot of money, and the business model of all of them is based on infinite growth, like cancer, so they'll never stop using those techniques to switch to something inferior in their eyes.
You won't be able to force them with legislation either. They'll either find loopholes, make the loopholes, or just pay the small fines for the few cases they'll receive, in any case treating the costs as the cost of business because it is still very profitable.
Parasites cannot be believed, if you have forgot.
There has never been a suggestion that Mozilla is planning to monetize PPA for themselves.
I think the user was speculating that Mozilla might want to embed ads in Firefox with this tech, or on their support and other websites.
The benefit is that it's better than what we have now.
Saying this is like accepting a new form of tax from a government that's widely known to be (monetarily) corrupt, in the hopes that with it they'll be content and will stop stealing and privatizing public money.