But you're talking in a very affirmative manner and apparently trying to say that one is "correct" and the other is not, while absolutely ignoring context and usage.
I recommend you either run yourself, or find on the web, a benchmark about not a single HTTP request, but an actual web page, requesting the html, the css, the js, and the images. Don't even need to go modern web, even any old pre 2010 design with no font or anything else fancy will do.
You will see that HTTP 1 and 1.1 are way, way worse at it that HTTP 2. Which is why HTTP 2 was created, and why it should be used. Also the sad joke that was domain rolling to trick simultaneous request per host configurations.
Overall, your point of view doesn't make sense because this is not a winner takes all game. Plenty of server should and do also run HTTP 1 for their usage, notably file servers and the likes. The question to ask is "how many request in parallel do the user need, and how important that they all finish as close to each other as possible instead of one after the other".
Similarily, HTTP3 is mostly about latency.