The most interesting chart is one of the last: Proportion of Failures over time. As expected, more recent product links are less likely to 404 or 5xx.
Going back to 2014, almost 1/3 of the featured links give a 4xx or a 5xx response. That’s a lot!
More surprising, links as recent as 2020 show a 1/4 failure rate. Those projects basically launched on PH, then shut down shortly afterward.
Moreover, this analysis can’t actually account for products that have been shuttered but still have landing pages online. It’s ultra cheap to keep a placeholder “Sorry we’re closed” page online, so I imagine a lot of these projects are shutdown but counted as “success”.
Subjectively, this matches what I’ve gathered from watching PH. Getting a PH featured product listing seems to be a badge of honor, but PH users aren’t really interested in using 99% of the products and the submitters aren’t actually interested in building them past proof of concept. Recently, the bulk of postings seem to be advertisements for paid information products or pay-to-join communities.