FWIW the original IBM BladeCenter platform was developed before BMCs so it had a much smaller service processor per blade connected over an out of band RS-485 management bus to a chassis management module. It was closer to Oxide than what's being sold today. And then "Windows needs VGA" kicked in.

IBM gear, aside from Thinkpads and the EduQuest PCs, have never been a thing I've gotten to interact with. Their documentation was always very good (which I think implies a certain level of overall competence) Given their massive legacy in datacenters I can imagine their PC-based server gear probably benefited.