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)