Best Practice of maintaining complex page

[mwskwong]

I'm taking inspiration from this webpage when building my own. As you can see, this design has most of its content on the index page and will make the index page quite complicated.

Currently, all JS files under the pages/ directory will be treated as new pages, and subdirectories will be treated as subpaths. So what's the best project structure for the kind of design I mentioned? Obviously, it is not a good pratice to put everything inside index.js. I currently have a separate directory called sections/index/ with all the sections (i.e. Home, About, Services, etc) of the index page. Do you think it is a good idea?