[CydeWeys]

It's the same data. What's different is essentially the transport layer for the information.

> Two protocols that have the same data would be quite redundant.

When one is plaintext, underspecified, and decades old, they're not. I don't think you realize how primitive WHOIS is; this is the entirety of its RFC: https://datatracker.ietf.org/doc/html/rfc3912 Note how it doesn't go any farther than "it's a plain text blob retrieved over TCP". Now contrast with the RDAP RFCs, which fully specify every aspect of how an RDAP service works:

https://datatracker.ietf.org/doc/html/rfc7480 https://datatracker.ietf.org/doc/html/rfc7481 https://datatracker.ietf.org/doc/html/rfc7482 https://datatracker.ietf.org/doc/html/rfc7483

Integrating with WHOIS is a nightmare, as every registrar/registry does it differently since there's no common specification other than "connect over TCP". RDAP is fully specified, so you can simply use a language-specific library and then inspect a strongly typed response object returned by said library to get specific information out of the response. It's a night-and-day difference, and there's obviously a reason for the new spec to exist even though it conveys the same data. It's absolutely not redundant.