That's solved in HTTP2 and other connection multiplexing protocols.

HTTP/2 runs on top of a single TCP connection so it's still vulnerable to TCP ordering requirements.

TCP will probably never have a mainstream solution to this, better to switch to UDP or QUIC instead.

While I agree QUIC is a better long term solution[1], saying TCP ordering affects HTTP/2 is misleading. It is true, but it is quite easy to avoid bad behavior by using TCP_NOTSENT_LOWAT (also created by Google), to avoid HoL blocking. For example, SPDY had a similar problem which was ameliorated by only sending when the water mark is low enough:

https://insouciant.org/tech/prioritization-only-works-when-t...

[1] https://news.ycombinator.com/item?id=12282898

Only sort of. You still have some HOL blocking problems with HTTP2 because you're still running on top of TCP. I recall this explicitly being one of the selling points of QUIC.

First resource I found on this matter from a quick search: https://engineering.salesforce.com/the-full-picture-on-http-...

SCTP