> You might also be interested in SCTP[1] from the year 2000, which also hasn't gotten any traction so far.
Probably partly because middleware boxes (e.g., firewalls) either didn't/don't support it and/or rules were written to only support "TCP" (as opposed to 'stream') or "UDP" (as opposed to 'dgram'; see also "DCCP").
Certainly that's a part, but it didn't help that SCTP has some fundamental low-level flaws.
Given that TCP also has at least one unfixable flaw, the only recommendation I can make is to use something UDP-based - which, to make sure you don't stomp on everybody else's traffic, means use the only popular one: QUIC (the layer beneath HTTP/3).
The protocol is specified by a byte in the IP packet; how many middleware boxes block everything except for ICMP, TCP, and UDP? What is the probability that a packet with that byte set to something unexpected actually gets from source to destination?
The “funny” thing is that http3 really really looks like a transport protocol encapsulated into… uso. Exactly because many middle boxes block anything that’s not a very well known protocol
> I assumed it's going to get adopted in no time due to how much of a ux improvement it would have been back in the day.
You might also be interested in SCTP[1] from the year 2000, which also hasn't gotten any traction so far.
[1]: https://en.wikipedia.org/wiki/Stream_Control_Transmission_Pr...