There's two big things missing in this discussion of the Semantic Web to me,

1. Developers. Historically Semantic Web was a lot of RDF & Sparql, which are both imo fairly hostile to developers. There were some decent libraries, but often written in a very oldschool style that made it difficult to even load or use, & with frankly pitiful documentation/tests. A lot of the databases/tooling was paid/proprietary.

The development story is looking much better. Oddball RDF & Sparql are joined by much more mainstream-dev friendly tools: Microdata which is pretty simple marked up HTML & JSON-LD which looks & works like JSON, with a little extra "context" sprinkled in at the top. Libraries are much improved & modernized & mainstream-dev compliant. Datastores like Apache Jena are far more used & there's a lot of ActivityPub & related json-ld-centric data-stores & systems being created & experimented with.

2. Users. The article talks about primary use cases for semantic web, and they are all huge massive industries, not people. We needed semantic web because it would help search. We needed semantic web because it would help social. We needed social web because it would help e-commerce (& look, an article from yesterday about just that![1]).

What's missing is end users. I don't mind that super-large data systems can do interesting things with semantic web. But to me, the purpose was always to enrich the information we users see online with our eyes with powerful & consistent data that our own machines can help use. Our navigator should be helping us, showing us what digital matter we are seeing on the page, rather than letting the page exist as one enormous standalone artifact implicitly composed of arbitrary text & images. There's meaning there, there's thing that we are working with, & semantic web gives us a common operating system for talking about things, & managing them.

Users are still somewhat missing from semantic web. Folks like ActivityPub are doing a wonderful & interesting job using Semantic Web to build common distributed platforms for social, where we can talk about digital matter like Shares and Photos and Favorites in a common way. For now, the semantic web tech remains under the hood, something abstract powering a client that abstracts over the semantic meaning to generate just another anonymous web page, filled with articles and photos and listens and viewings & other social entities, but presented through the veneer of the application, not as discrete social objects unto themselves. I think we're only just starting to explore how to open the Semantic Web up, how to represent semantic data entities & data stores, in a way that will let users interact directly with digital objects, rather than needing the artifice & instrumentation of the application. But this is pretty deep conjecture. What I think is clearer to say is that the end-user has, until very recently, has not seen or understood how semantic web technology might be helping them; it's been a tool for businesses & big data. I look forward to the interesting era of Semantic Web, the era now breaking upon us, when we get to explore how having structured meaningful data can be good for individuals, persons, for personal computing, for small & medium data, & especially, for us to begin to communicate with each other over better structured data. And I think JSON-LD, ActivityPub, & the semantic web is, by far, the most promising & straightforward way to explore these virtues of structured communication.

By contrast, the article's talk about "what's next" is yet more academic projects, machine learning, & trying to represent more things (like actions, which is something absolutely core to what ActivityPub does: represent activities[2]!).

[1] https://news.ycombinator.com/item?id=24557027

[2] https://www.w3.org/TR/activitystreams-vocabulary/