I feel that something very crucial is touched upon here.
Since the early days of the Semantic Web I’ve felt - like other proponents of the technology - that linked data would allow applications to be taken to a new, higher level than was possible before. And I was eagerly awaiting all the exciting uses that would become available over time. Though there’s some very prominent and successful applications since then, like Google Knowledge Graph, OpenGraph and a couple others until now imho the tech has undersold and overpromised. I am still fervently hoping for it to take flight and get more widespread adoption.
One of the problems I think are in the realms of ‘productization’. From the very start the technology has not been easily accessible, not developer-friendly, the true benefits not immediately obvious. Always the answer to questions people like @dynamoRando are asking is something like “If only you take the deep-dive, go through the rabbit hole, you will see the light and the world will be your oyster” 
Most applications I’ve seen to date are firmly in the academic world, or they are for the vast majority fully tech-focused, UX/UI comes later, and product website, good documentation after that.
Linked data / semantic applications should “sell” themselves better to the outside world. That so little of that is happening is imho a very inhibiting factor that slows the evolution of the entire field. When technologists don’t get it, they move own to lower-hanging fruits, greener pastures. When diving into linked data most of what you find stems from the Semantic Web hype that has long past and where link rot is setting in. There’s great developments still - like Solid - but most of the information is at experts level. Insiders of the field. For those that ventured into the rabbit hole before.
This is also the case for the Fediverse where federated app developers treat ActivityStreams / ActivityPub formats as plain JSON and just throw a @context in it at the last moment for good measure and to comply to the spec. With apps evolving like that the Linked Data parts of the story become a harder sell all of the time. And that saddens me, as I believe in its potential.
I’ve said this before on this forum. Much of the Solid Project seems to aim at professional / corporate / commercial adoption first and foremost, and though that strategy might be a good way to come to widespread adoption, my personal impression is that new technologies find adoption fastest if they have a high appeal to the developer community. And that would entail more focus on the community aspects and cross-community collaborations than there exists now (as far as my awareness is).