[colept]

The concept is beautiful, but it goes against the principles of how people interact with a computer.

Scrolling is not an element of the web page, it's an element of the computer. If it's unique to every page, it's jarring and taxing to have to re-learn every website. Some sites use black backgrounds. Textareas use scrollbars too.

The reason scrollbars work is because they look the same consistently for each individual platform. You don't have to learn a new scrollbar for every page (although some break this pattern anyway). When they're the same, it's less mentally to parse for each page load so that the user can focus on what's really important: the content.

[xpostman]

Have you faced any complications in understanding how navigation is performed on the page? (if we imagine that the content is not actually related to the subject and does not explain how the indication works)

[colept]

Complications? My belief is that good UI is there, but not noticed. You shouldn't have to ask how to interface with a website.