> it was designed in 1998 by networking gear companies
That's false. Firstly, rfc1883 was published in 1995 which means work started some time before that, and the RFC process included operating system vendors and RIR administrators. The primary author of rfc1883 worked at Xerox Parc, and the primary author of rfc1885 worked at DEC. Neither were networking gear companies.
That's a proposed standard, looks like what obsoletes is the draft standard.