[dieulot]

HTTP/2 “pipelining” (multiplexing) is still there and works as intended; but bundling is still much more efficient.

This article delves into just that: https://csswizardry.com/2023/10/the-three-c-concatenate-comp... The first pair of waterfall graphics illustrates the problem clearly.

(What you vaguely remember as not working as intended is probably Server Push).