There was never any incentives aligned to make the Semantic Web work. For it to work, page authors had to go through the trouble of making their own content com

There was never any incentives aligned to make the Semantic Web work. For it to work, page authors had to go through the trouble of making their own content compatible, but it didn't really buy them anything in return and for big content producers it removed their main revenue source -- ads. As a result, the places that had lots of information never bothered, and small users never bothered, and the SW petered out. In some ways it's similar to what we see in certain news sites. They only link to other pages on their own site even though it would be trivial to link out to the original information pages. Sites will even host public documents in in-line PDF readers in order to not link back to completely publicly available government sites -- scientific and engineering advancements are often vaguely and imprecisely talked about with no link to the original paper or announcement from the source. By living on ad revenue, these sites want to roach motel you into their hypertext jail and the result is information gets twisted and misreported where it propagates and is repeated in other places. News sites will even reference each other without linking back to the other site's original content. Ads killed the Semantic Web.