Often, new technologies and tools will be created to facilitate the work in the real world.
Gadgets are usually designed with the aim of eliminating repetitive work and automating routine tasks.

In the real world, we used newspapers, magazines, textbooks, story books and short stories, and different archives and albums.

But nowadays, most of the above cases entered the virtual world in a simulated form. Even some of the above are not very useful in our lives.

For every simulation and implementation in the computer world, we need at least a platform and an implementation language.
Of course, html is not a programming language and is only markup (conditions and mathematical functions cannot be implemented).

The emergence of html with the need to simulate a newspaper

In journalism, each page has its own structure. What kind of news from which category should be placed next to what content along with image or text. Or the titles and lists are placed next to each other.
And finally, the content was produced with their own special framework. Here, the need to edit the visual content in terms of size and font was also raised. For this reason, from the beginning of the design, the need for an auxiliary language was felt only for visual editing.

As a result, it can be said that in order to implement a newspaper on a computer, a language that can display the structure and content (html) is needed.
And a language that can simulate visual content (css) was found.