I’m curious about the development of multiformats, and whether alternatives like Apache Avro were considered. What do people see as the benefits or tradeoffs in multiformats vs other self-describing formats?
They’re different things with different goals. Multiformats is a collection of patterns and techniques that allow you to make your data future-proof. Avro is a “data serialization system” that seems primarily focused on specifying schemes for data serialization.
If people use multiformats patterns in their data, for example using multihash pattern when generating hash identifiers, their data will age more gracefully. That applies to Avro users as much as it applies to anyone else.