HTTP/3 has a better goal in that it aims to push these elements back down to the transport layer using QUIC, in HTTP/2 transport abstractions bubbled up to the protocol layer making for a messy abstraction. HTTP/2 is a leaky abstraction and blends too much of the transport and protocol layers and unnecessarily complex.

Though I will add that much of the protocol and standards work in recent years or even the last 5-10 has largely been companies aiming to take control of the standards by implementing standards that benefit them the most over maybe sensible simplifying, adding complexity to own it more. That definitely is a factor and HTTP/2 was rushed probably for this reason.

SCTP would be doable as it is a transport layer and yes difficulty in rolling it out, but Google went after QUIC, which is also a transport layer and is similar to SCTP (UDP capabilities or essentially a transport version of RUDP mixed with ordering/verification), because they also call the shots on that. It makes sense for Google to push that but does it make sense for everyone to just allow that? People have to understand that standards are now pushed company level rather than from engineering solely. The needs of HTTP/2 went beyond a better system, it ventured into control the standards and market standards territory.

Hopefully HTTP/3 is better and less complexity, but judging by who wants it in and how companies want to control these layers more, I have my doubts. We now have 3 HTTP protocol layers to support, more and more it will box out engineers from being able to compete or other browsers/web servers to compete. I don't know that the pros outweigh the cons in some of these scenarios.

Who really gains/ed from HTTP/2 HTTP/3? UDP was always available as well as reliable UDP. HTTP/2 and HTTP/3 feel more like a standards grab with minimal benefits but major benefits to the pushers. I am not against progress in any way, I am against power grabs and iterations that provide little benefits from major overhauls and 'second-system syndrome' as well as complexity rather than simplicity to some of those ends.

Did we really benefit from obfuscating protocol layers of HTTP (the HyperTEXT Transfer Protocol) into binary? What did we gain? We lost plenty, easier debugging, simplification, control of the standard, competition etc. Hopefully we gained from it but I am not seeing it. We already had encryption and compression to stop ad networks/data collection, binary gains are minimal for lots of complexity. Simplification was destroyed for what? Resource inlining breaks caching. Multiplexing is nice but it came at great cost and didn't really improve the end result.

HTTP/2 reminds me of the over complexity in frameworks, SOAP vs REST, binary vs text, binary JSON and many other things that were edge cases that now everyone has to deal with. As engineers we must take complexity and simplify it, that is the job, I don't see lots of that in recent years with standards and development. Minimalism and simplicity should be the goal, complexity should be like authority, it should be questioned harshly and be allowed only when there is no other way.

Making another version and more complexity is easy, making something simple is extremely difficult.