Man, what a perverted definition of success... They failed in being useful to the end users, but they damned sure made their engagement KPI look good, and also got a few ad impressions on the way.
What you seem to overlook is that the people curating the site and setting up duplicate links don't see a penny of revenue. There is extreme misalignment between them and the actual stakeholders. Nowadays the site staff/owners are seen by the meta community basically as active saboteurs.