Earlier quoted context omitted.
Everyone realises that. They just understand that it is a big problem with CSS. People wanted app-like layouts since before CSS was a thing. The problem is the people who designed CSS had an ideological axe to grind. They believed that HTML should only be used for document layout.
But that is the fundamental problem behind all of web nowadays: It was initially designed for documents ; there are precursors for this entire HTML stuff (hypercards and similar things). Funnily enough, there existed tech even back then that was much much better at dealing with actual applications and their requirements. Unfortunately, many stupid idiots decided to use the "web" for that instead and mangle something…
It was a hack but it worked better to serve the needs of the users.