I agree that OpenAPI is how I would prefer to see an API documented and defined (especially since there are tools to allow you to use a good spec to automatical

I agree that OpenAPI is how I would prefer to see an API documented and defined (especially since there are tools to allow you to use a good spec to automatically generate your client routines), but I think many these RFCs are a bit different, in that they may define how records should show relations to each other, or how to use Oath, etc, which is something OpenAPI documents, but not something it prescribes. Where OpenAPI defined how to implement a client or server interface for an API, these RFCs seem to define some best practices for how you would do so. That is, if OpenAPI is analogous to a dump of a database schema, these RFCs are more analogous to a set of best practices on database naming, data types to use, which levels of normalization are best for which types of data, etc.