The academic semantic web asked authors to model their domain correctly. Schema.org asked them to add a bit of JSON so their page would look better in search results. Only one of those was ever going to reach scale.

What it buys you

• Rich results in search: ratings, breadcrumbs, event dates, FAQ expansion.
• Machine-readable meaning for aggregators and assistants that will never read your CSS.
• A vocabulary you do not have to invent or defend, which removes the argument that killed most ontology projects.

Doing it without regret

Use JSON-LD in a script tag rather than microdata woven through the markup — the coupling between your semantics and your layout is the thing that rots. Generate it from the same source as the rendered content so the two cannot disagree, and validate it in CI. Structured data that contradicts the page is worse than none, and search engines treat it as exactly that.