From what I understand, SemWeb is/was pretty much TBL's pet project at W3C, and the one thing he was interested tinkering with. SemWeb such as RDF, SPARQL, OWL,

From what I understand, SemWeb is/was pretty much TBL's pet project at W3C, and the one thing he was interested tinkering with. SemWeb such as RDF, SPARQL, OWL, etc. isn't terrible to work with, and has found it's niches; for example I'm working right now on a project making heavy use of graph DBs and SPARQL for biochem, and the standardization has profoundly helped F/OSS and commercial software funding in that area, and has helped funding research (eg. identifying tractable fragments of first order logic with OWL/2). But OTOH the SemWeb stack feels very much a design-by-comittee, with lots of "reuse" of other unrelated W3C tech such as XML, and I don't think it will ever become mainstream apart from things such as Wikimedia's public data sets published as RDF where it seems a good fit. The more problematic side with TBL's SemWeb love affair is that it has resulted in web core standardization to become neglected at W3C. For example, W3C HTML was last published in 2017 as a recommendation (with plans to merely "bless" WHATWG snapshots going forward, which however hasn't happened so far). Likewise, the SVG2 effort (with little but still welcome additions/cleanup compared to SVG1.1) has stalled, etc.