That would truly be a foolish argument to make. However the argument I am making is, is ad supported content is one of the few monetary schemes which allows you to produce a product that allows for poorer people to part of the audience.

They are still paying for it with every product they buy because prices include the ad budgets. At best you could argue that poorer people are subsidized by richer people because they buy more and therefore pay for a larger share of the ad budget but ads certainly don't make stuff free for poorer people. Whether they would be better off with no advertising at all, i.e. if they still pay a larger share of the ad budgets than what the ad supported stuff they consume is worth, I can not tell.

Your argument supposes that you know the surplus earned by brands segmented by user wealth group (how much money users give to brands after using the service - how much they would without)

That's a strawman. (And wow, am I surprised to be able to say that to anyone on HN).

What's actually argued is advertisements aren't 100% effective, in that they can't force you to purchase a product as a mind-controller.

Ads let you know a product exists, may convince you that it's worthwhile or better than competitors, and offer reminders to keep the idea of the product on your mind. However, that's all the same things a carefully crafted in person sales-pitch could do, and sales pitches aren't mind-control even though they are far far more effective than any number of internet banner ads can be.