Lounge

Generally speaking authoring is a huge subject. People make books, manuscripts, articles, worksheets, presentation slides, e-books, live-books, animated learning material; the list is endless.

Your specific question "Is this the best?" I think, is specific to your audience, which only you know. If you were happy with Goodle Docs, then why worry about all the rest? Google Docs have the advantage that they are "HTML", made for the computer screen, as opposed to Office documents which are optimized for paper. The slight downside is that Google Docs are hosted in a different place, not in your LMS. Those "external" things have the habit of vanishing from the LMS as time goes on. I strongly prefer to have *everything* in the LMS.

The next obvious question is, what is the equivalent to Google Docs in Moodle. Again, there are too many, starting from the Page resource, Book module, Blogs more statics ones to  Glossary activity, Journal module, Diary, IMS content package, Lesson activity, Wiki activity, H5P, SCORM activity, etc for dynamic ones.

I see that you've already discovered the Book activity. https://moodle.org/mod/forum/discuss.php?d=453724#p1823155