This assumes that poor people's attention is liquid and can readily be turned to cash whenever they please.
It doesn't matter how much you think my attention is "really worth". If I want the service now, have no cash, but can pay with my attention, I am strictly more enabled than if the service only accepts cash.
I make no assumption there.
The fork between (1), (2) is how much cash their attention is actually turned into.
To put it another way: what's the attention of a poor person really worth, in dollars? Answer is always less than or equal to the amount they can spend.
The comment you were responding to said that the free tiers were a boon for the poor and you responded that they (under the fork of interest) "left poor people poorer".
I mean I supposed every transaction leaves someone poorer of something and richer in something else. I'm not sure of the point though.
I concede that if the ad companies are willing to forgo collecting X dollars in exchange for showing you an ad then it must be worth >=X dollars to the ad company for the person to see the ad.
But it remains true that the poor person has no way to convert their attention directly into X dollars, and all that taking away the free tier does is make it so that someone who would have made a trade (of their attention for a service) cannot do so.