if people are reading the articles through wayback, then they aren't making any money because no data is harvested and no click-thrus or impressions or whatever the metric is are registered.
People are willing to post links to paywalled articles when there are ways for people not currently inclined to subscribe to read them. Even if 97% of the current non-subscribers bypass the paywall, having 3% become subscribers is very useful, especially if they become recurring subscribers.
If posting the link instead implies that the 97% of people not currently willing to subscribe can't read it, then people instead post a link to a publication their audience can read, in which case the first publication gets actually 0%.
If posting the link instead implies that the 97% of people not currently willing to subscribe can't read it, then people instead post a link to a publication their audience can read, in which case the first publication gets actually 0%.