We explained the need for a centralized metadata repository here https://blog.open-metadata.org/announcing-openmetadata-20399... . Please give it a read.

* It seems like DataHub has an async Kafka ingestion approach while OpenMetadata is API

We do not use Kafka by default. If someone needs kafka they can add it. However for Metadata APIs, we do not feel like Kafka is needed. Lot of projects are getting dependent on Kafka and calling it as real-time. Its unnecessary burden on users who are going to operate in production for 99% of use-cases Kafka is not needed, coming from a Kafka committer :)

2. Yes all of our APIs and Entity definitions are generated using JsonSchema. For us, Json Schema has been awesome, all of our backend / ingestion and UI is generated from JsonSchema and its easy to extend and add new models when needed

3. IMO, we have much more coverage , you can look at the types available here https://github.com/open-metadata/OpenMetadata/tree/main/open... and we are support JsonSchema as a type from a long time

We at OpenMetadata(https://open-metadata.org) use JsonSchema extensively to define the metadata standards. JsonSchema is one of the reasons we are able to ship and get the project to what it is today in quick time. More about it here https://www.youtube.com/watch?v=ZrVTZwmTR3k