Earlier quoted context omitted.
Just because you haven't been exposed this issue doesn't mean it doesn't exist. "the real situation", "no one", "in real projects", "never pop up"...give me a break lol.
One can reasonably well guess/know the expected input sizes to their programs. You ain’t (hopefully) loading your whole database into memory, and unless you are writing a simulation/game engine or another specialized application, your application is unlikely to have a single scorching hot loop, that’s just not how most programs look like. If it is, then you should design for it, which may even mean changing programmi…
If everything was built with constraints like "this must serve user input so quickly that they can't perceive a delay", we would probably be a lot better off across the entire board.
We should try to steal more ideas from different domains instead of treating them like entirely isolated universes.