[Rygian]

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...

[MrVandemar]

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.

[Rygian]

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