> What else remains?

SPARQL. It's useful beyond Semantic Web, as evidenced by the raise of projects such as GraphQL. It can replace proprietary REST APIs and make the Web more connected and open. For e.g. see this short talk by Ruben Verborgh [1] and projects like Solid [2].

[1] https://youtu.be/LUF7plExdv8

[2] https://solid.mit.edu/

I chuckled on the EU research grants part. My God, when I remember the monstrosities I was thinking up just to bodge in Semantic Web/Linked Data. Those guys are purely fueled by buzzwords. Maybe we met somewhere :) .

"Semantic data is the future and always will be" - unknown author.

Wikidata is built mostly on RDF ideas. For example, there's SPARQL query interface for it: https://query.wikidata.org/

Schema.org is heavily used by search engines and metadata in its format is found on many websites. It's an RDF-based format.

What do you think Google, Facebook, Siri and Alexa use for their underlying knowledge graphs?

Ha, my sole experience of RDF was on an EU-funded research project :)