It's usually done by different people with different job descriptions.

A writer's output are manuscripts, works of art.

A publisher's output is a commercial offering of books, a business.

[1] https://askanydifference.com/difference-between-author-and-p...

I agree, but the latter can also be a work of art. Typesetting is definitely something that can be done right or wrong, and sometimes to a breathtakingly high standard.

The publisher engages or hires typesetters, as part of the publishing process.

Scriveners tools are designed to help a person write like keeping track of timelines, character sheets, and the like.

It sounds like the other product has tools for typesetting and layout, which are tools for publishing your finished work.