On chain anchoring is excellent as a second layer.

On chain anchoring is excellent as a second layer. It is a timestamped witness. But if you jump straight to chain you risk creating a strong proof of something that is poorly defined, poorly discovered, or hard to interpret later.

JSON LD is a better first layer because it does three things the chain does not reliably do on its own.

It makes the claim readable to ordinary tools and future crawlers

It makes the claim portable across domains and platforms

It separates discoverability metadata from the verification artifact. - Rico Roho (Beyond the Memory Hole)

Context: Beyond the Memory Hole