Which is an example of ossification, in this case at the IP level.
From context, I assumed detaro was referring to an ossification of SCTP.
Ah, yes, that wasn't quite clear, sorry. No, I was referring to the ossification of middleboxes/OSes/knowledge/... that made it unviable to support a new IP protocol alongside the existing ones for the general internet case.
Sctp over UDP is a thing and still hasn't gained much general public use over the net... Sadly!
SCTP over DTLS over ICE over UDP is used quite a lot though!
That's how DataChannels in WebRTC were specified a while ago, and it's the only mechanism to do browser to browser communication.
Oh yes, when I discovered SCTP I felt so sad for all time I and hundred others had implemented part of its featureset over the last 30 years... I mean, it was packed with great features like separate streams, packet-based, multi-homing and multipath. It felt so right playing with it. Alas, even in my company I failed to convince it was a great replacement for layers upon layers of working udp code. I think it came too late...
That's not because of ossification, it's because of middleware boxes like NATs and firewalls that will refuse to pass anything that isn't TCP, UDP, or ICMP.