Why don't sub-sections use the list.html template?

[tut]

@realpixelcode

Do I have to manually set up an _index.md file for each sub-section

Why don’t you test it and see the result? A branch bundle needs an _index.md file.

Explanation of Page Bundles

content/ └── books ├── book-1.md <-- page ├── book-2 <-- page bundle, specifically a leaf bundle │ ├── cover.jpg │ └── index.md └── book-3 <-- page bundle, specifically a branch bundle ├── chapter-1.md ├── chapter-2.md ├── cover.jpg └── _index.md https://gohugo.io/content-management/page-bundles